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Sample records for congenital myotonic dystrophy

  1. Myotonic Dystrophy and Facioscapulohumeral Muscular Dystrophy Registry

    ClinicalTrials.gov

    2017-08-11

    Myotonic Dystrophy; Facioscapulohumeral Muscular Dystrophy; Muscular Dystrophy; Myotonic Dystrophy Type 1; Myotonic Dystrophy Type 2; Congenital Myotonic Dystrophy; PROMM (Proximal Myotonic Myopathy); Steinert's Disease; Myotonic Muscular Dystrophy

  2. Myotonic Dystrophy Family Registry

    ClinicalTrials.gov

    2016-03-28

    Myotonic Dystrophy; Congenital Myotonic Dystrophy; Myotonic Dystrophy 1; Myotonic Dystrophy 2; Dystrophia Myotonica; Dystrophia Myotonica 1; Dystrophia Myotonica 2; Myotonia Dystrophica; Myotonic Dystrophy, Congenital; Myotonic Myopathy, Proximal; PROMM (Proximal Myotonic Myopathy); Proximal Myotonic Myopathy; Steinert Disease; Steinert Myotonic Dystrophy; Steinert's Disease; Myotonia Atrophica

  3. [A neonatal case of congenital myotonic dystrophy].

    PubMed

    Ghizzi, C; Cavalli, C; Benedetti, M; Bolognani, M; Biban, P

    2000-01-01

    Congenital myotonic dystrophy is a rare autosomal disease, caused by an increased number of cytosine-thymine-guanine (CTG) trinucleotide on chromosome 19q. In the neonatal period the most peculiar clinical features are arthrogryposis, hypotonia, facial diplegia, respiratory and feeding difficulties. Clinical and electrical myotonic discharges are difficult to elicit in the newborn. We report a case of congenital myotonic dystrophy in a female newly born presenting with hypotonia, diaphragmatic paralysis, facial diplegia, and contractures of hips, knees and ankles. The diagnosis was confirmed by genetical study on lymphocyte DNA.

  4. Congenital myotonic dystrophy in Britain. II. Genetic basis.

    PubMed Central

    Harper, P S

    1975-01-01

    Genetic analysis of 54 sibships containing 70 patients with congenital myotonic dystrophy has shown paternal transmission in only one case, the disorder being maternally transmitted in 51 sibships. No instance of new mutation was found. At least half the sibs were unaffected; 9 sibs were affected without definite congenital involvement. No evidence for genetic heterogeneity was found, most affected mothers having few or no symptoms. There was no disturbance of sex ratio for the affected grandparents, nor in the sibships of the affected parents. The genetic data from this study and from previous published reports support the clinic evidence that the congenital form of myotonic dystrophy results from a maternal intrauterine factor affecting those individuals carrying the myotonic dystrophy gene. PMID:1167063

  5. Congenital myotonic dystrophy can show congenital fiber type disproportion pathology.

    PubMed

    Tominaga, Kayo; Hayashi, Yukiko K; Goto, Kanako; Minami, Narihiro; Noguchi, Satoru; Nonaka, Ikuya; Miki, Tetsuro; Nishino, Ichizo

    2010-04-01

    Congenital myotonic dystrophy (CDM) is associated with markedly expanded CTG repeats in DMPK. The presence of numerous immature fibers with peripheral halo is a characteristic feature of CDM muscles together with hypotrophy of type 1 fibers. Smaller type 1 fibers with no structural abnormality are a definitive criterion of congenital fiber type disproportion (CFTD). Nonetheless, we recently came across a patient who was genetically confirmed as CDM, but had been earlier diagnosed as CFTD when he was an infant. In this study, we performed clinical, pathological, and genetic analyses in infantile patients pathologically diagnosed as CFTD to evaluate CDM patients indistinguishable from CFTD. We examined CTG repeat expansion in DMPK in 28 infantile patients pathologically diagnosed as CFTD. Mutation screening of ACTA1 and TPM3 was performed, and we compared clinical and pathological findings of 20 CDM patients with those of the other cohorts. We identified four (14%) patients with CTG expansion in DMPK. ACTA1 mutation was identified in four (14%), and TPM3 mutation was found in two (7%) patients. Fiber size disproportion was more prominent in patients with ACTA1 or TPM3 mutations as compared to CFTD patients with CTG expansion. A further three patients among 20 CDM patients showed pathological findings similar to CFTD. From our results, CDM should be excluded in CFTD patients.

  6. [Congenital myotonic dystrophy in a Neonatal Intensive Care Unit: case series].

    PubMed

    Domingues, Sara; Alves Pereira, Clara; Machado, Angela; Pereira, Sandra; Machado, Leonilde; Fraga, Carla; Oliveira, Abílio; Vale, Isabel; Quelhas, Ilídio

    2014-02-01

    Steinert myotonic dystrophy is a multisystemic disease, autosomal dominant, with a wide spectrum of severity and clinical manifestations. The most severe form is one that manifests in the neonatal period, called congenital myotonic dystrophy. This condition is distinguished by overall hypotonia at birth and respiratory function compromise. Complications are frequent, mainly psychomotor development delay, growth failure, food difficulties and constipation. It is associated with a poor prognosis, with an overall mortality of up to 50% of severely affected children. We present five patients with congenital myotonic dystrophy in order to describe clinical manifestations, diagnosis, treatment and prognosis. Existing data in the literature on psychomotor development, complications and prognosis of survivors with congenital myotonic dystrophy are scarce. In our case studies, we have found significant chronic psychomotor limitations.

  7. Myotonic Dystrophy

    PubMed Central

    Thornton, Charles A.

    2014-01-01

    Myotonic dystrophy (dystrophia myotonica, DM) is one of the most common lethal monogenic disorders in populations of European descent. Myotonic dystrophy type 1 (DM1) was first described over a century ago. DM1 is caused by expansion of a CTG triplet repeat in the 3' non-coding region of DMPK, the gene encoding the DM protein kinase. More recently a second form of the disease, myotonic dystrophy type 2 (DM2) was recognized, which results from repeat expansion in a different gene. The DM2 expansion involves a CCTG repeat in the first intron of Zinc Finger 9 (ZNF9). Both disorders have autosomal dominant inheritance and multisystem features, including myotonic myopathy, cataract, and cardiac conduction disease. Studies suggest that the shared clinical features of DM1 and DM2 involve a novel genetic mechanism in which repetitive RNA exerts a toxic effect. The RNA toxicity stems from the expanded repeat in the transcripts from the mutant DM alleles. This chapter will review the clinical presentation and pathophysiology of DM, and discuss current management and future potential for developing targeted therapies. PMID:25037086

  8. Myotonic dystrophy.

    PubMed

    Thornton, Charles A

    2014-08-01

    Myotonic dystrophy (dystrophia myotonica, DM) is one of the most common lethal monogenic disorders in populations of European descent. DM type 1 was first described over a century ago. More recently, a second form of the disease, DM type 2 was recognized, which results from repeat expansion in a different gene. Both disorders have autosomal dominant inheritance and multisystem features, including myotonic myopathy, cataract, and cardiac conduction disease. This article reviews the clinical presentation and pathophysiology of DM and discusses current management and future potential for developing targeted therapies.

  9. Immunocytochemical localization of myotonin protein kinase on muscle from patients with congenital myotonic dystrophy.

    PubMed

    Tachi, N; Kozuka, N; Ohya, K; Chiba, S; Kikuchi, K

    1996-10-01

    Using a polyclonal anti myotonin-protein kinase (M-PK) antibody against synthetic M-PK peptides corresponding to part of the amino acid sequence, and the immunohistochemical analysis of indirect immunoperoxidase, we have investigated localization of M-PK on muscle from patients with congenital myotonic dystrophy. In congenital myotonic dystrophy (MD) patients, one month and 3 months old, M-PK was weakly expressed at sarcolemma of muscle fibers. In congenital MD patients from 2 to 9 years of age, M-PK was clearly expressed at sarcolemma of muscle fibers. M-PK of immature muscle is weakly expressed at sarcolemma. With aging, M-PK is clearly expressed at sarcolemma of muscle from MD patient and normal control.

  10. The impact of congenital and childhood myotonic dystrophy on quality of life: a qualitative study of associated symptoms.

    PubMed

    Johnson, Nicholas E; Luebbe, Elizabeth; Eastwood, Eileen; Chin, Nancy; Moxley, Richard T; Heatwole, Chad R

    2014-07-01

    This study systematically evaluated the symptoms associated with congenital and childhood myotonic dystrophy, and how these symptoms affect health related quality of life. We conducted interviews with patients affected by congenital or childhood myotonic dystrophy and their affected parent to identify which symptoms have the greatest effect on their lives. Each interview was recorded, coded, and analyzed using a qualitative framework technique. In 34 interviews with 13 parents and 21 patients, we identified 189 symptoms, representing 22 themes in physical, emotional, social, and disease-specific quality of life. Communication difficulties, cognitive impairment, and social role limitations were the most frequently identified themes. These interviews identified multiple themes and symptoms, some previously under-recognized, which play a key role in the disease burden associated with congenital and childhood myotonic dystrophy.

  11. Balance outcomes following a tap dance program for a child with congenital myotonic muscular dystrophy.

    PubMed

    Biricocchi, Charlanne; Drake, JaimeLynn; Svien, Lana

    2014-01-01

    This case report describes the effects of a 6-week progressive tap dance program on static and dynamic balance for a child with type 1 congenital myotonic muscular dystrophy (congenital MMD1). A 6-year-old girl with congenital MMD1 participated in a 1-hour progressive tap dance program. Classes were held once a week for 6 consecutive weeks and included 3 children with adaptive needs and 1 peer with typical development. The Bruininks-Oseretsky Test of Motor Proficiency, second edition (BOT-2) balance subsection and the Pediatric Balance Scale were completed at the beginning of the first class and the sixth class. The participant's BOT-2 score improved from 3 to 14. Her Pediatric Balance Scale score did not change. Participation in a progressive tap dance class by a child with congenital MMD1 may facilitate improvements in static and dynamic balance.

  12. Transient complete atrioventricular block in a preterm neonate with congenital myotonic dystrophy: case report.

    PubMed

    Kim, Hee Na; Cho, Young Kuk; Cho, Joo Hyun; Yang, Eun Mi; Song, Eun Song; Choi, Young Youn

    2014-06-01

    Congenital myotonic dystrophy (CMD) is an inherited neuromuscular disorder with cardiac rhythm abnormalities that may occur as a child grows. No report has described complete atrioventricular (AV) block detected in a neonate with CMD. We report a floppy infant of 31(+4) weeks gestation with complete AV block at birth, who was diagnosed with CMD by Southern analysis. She recovered from complete AV block 32 hr after temporary transcutaneous pacing was applied. To the best our knowledge, this is the first recorded case of a complete AV block accompanied by CMD during the neonatal period. When a newborn has a complete AV block, the physician should consider the possibility of the CMD and conduct a careful physical examination.

  13. Contribution of molecular analyses to the estimation of the risk of congenital myotonic dystrophy.

    PubMed

    Cobo, A M; Poza, J J; Martorell, L; López de Munain, A; Emparanza, J I; Baiget, M

    1995-02-01

    A molecular analysis of the maternal and child CTG repeat size and intergenerational amplification was performed in order to estimate the risk of having a child with congenital myotonic dystrophy (CMD). In a study of 124 affected mother-child pairs (42 mother-CMD and 82 mother-non-CMD) the mean maternal CTG allele in CMD cases was three times higher (700 repeats) than in non-CMD cases (236 repeats). When the maternal allele was in the 50-300 repeats range, 90% of children were non-CMD. In contrast, when the maternal allele was greater than 300 repeats, 59% inherited the congenital form. Furthermore, the risk of having a CMD child is also related to the intergenerational amplification, which was significantly greater in the mother-CMD pairs than in the mother-non-CMD pairs. Although the risk of giving birth to a CMD child always exists for affected mothers, our data show that such a risk is considerably higher if the maternal allele is greater than 300 repeats.

  14. Congenital and childhood myotonic dystrophy: Current aspects of disease and future directions

    PubMed Central

    Ho, Genevieve; Cardamone, Michael; Farrar, Michelle

    2015-01-01

    Myotonic dystrophy type 1 (DM1) is multisystem disease arising from mutant CTG expansion in the non-translating region of the dystrophia myotonica protein kinase gene. While DM1 is the most common adult muscular dystrophy, with a worldwide prevalence of one in eight thousand, age of onset varies from before birth to adulthood. There is a broad spectrum of clinical severity, ranging from mild to severe, which correlates with number of DNA repeats. Importantly, the early clinical manifestations and management in congenital and childhood DM1 differ from classic adult DM1. In neonates and children, DM1 predominantly affects muscle strength, cognition, respiratory, central nervous and gastrointestinal systems. Sleep disorders are often under recognised yet a significant morbidity. No effective disease modifying treatment is currently available and neonates and children with DM1 may experience severe physical and intellectual disability, which may be life limiting in the most severe forms. Management is currently supportive, incorporating regular surveillance and treatment of manifestations. Novel therapies, which target the gene and the pathogenic mechanism of abnormal splicing are emerging. Genetic counselling is critical in this autosomal dominant genetic disease with variable penetrance and potential maternal anticipation, as is assisting with family planning and undertaking cascade testing to instigate health surveillance in affected family members. This review incorporates discussion of the clinical manifestations and management of congenital and childhood DM1, with a particular focus on hypersomnolence and sleep disorders. In addition, the molecular genetics, mechanisms of disease pathogenesis and development of novel treatment strategies in DM1 will be summarised. PMID:26566479

  15. Influence of the sex of the transmitting grandparent in congenital myotonic dystrophy.

    PubMed

    López de Munain, A; Cobo, A M; Poza, J J; Navarrete, D; Martorell, L; Palau, F; Emparanza, J I; Baiget, M

    1995-09-01

    To analyse the influence of the sex of the transmitting grandparents on the occurrence of the congenital form of myotonic dystrophy (CDM), we have studied complete three generation pedigrees of 49 CDM cases, analysing: (1) the sex distribution in the grandparents' generation, and (2) the intergenerational amplification of the CTG repeat, measured in its absolute and relative values, between grandparents and the mothers of CDM patients and between the latter and their CDM children. The mean relative intergenerational increase in the 32 grandparent-mother pairs was significantly greater than in the 56 mother-CDM pairs (Mann-Whitney U test, p < 0.001). The mean expansion of the grandfathers (103 CTG repeats) was also significantly different from that seen in the grandmothers' group (154 CTG repeats) (Mann-Whitney U test, p < 0.01). This excess of non-manifesting males between the CDM grandparents' generation with a smaller CTG length than the grandmothers could suggest that the premutation has to be transmitted by a male to reach the degree of instability responsible for subsequent intergenerational CTG expansions without size constraints characteristic of the CDM range.

  16. Fetal akinesia-hypokinesia deformation sequence (FADS) in 2 siblings with congenital myotonic dystrophy.

    PubMed

    Lidang Jensen, M; Rix, M; Schroder, H D; Teglbjaerg, P S; Ebbesen, F

    1995-01-01

    Two premature siblings described herein had clinical features comparable to the fetal akinesia-hypokinesia deformation sequence (Pena-Shokeir syndrome) with polyhydramnios, intrauterine growth retardation, pulmonary hypoplasia, short umbilical cord and lethality. Autopsy revealed no thoracal or abdominal viscera anomalies and examination of the brain, spinal cord and peripheral nerves did not disclose any pathological changes. Light microscopy, immunohistochemistry and electron microscopy of skeletal muscles demonstrated immature muscles with some fibril disorganisation and abnormal immunoreactivity for actin and desmin. Subsequent molecular genetic analysis revealed a maternal diagnosis of myotonic dystrophy. The retarded growth and maturation of skeletal muscle observed in the presented cases correspond with previous findings in neonatal myotonic dystrophy. A well-defined myopathy can thus result in the fetal akinesia-hypokinesia deformation sequence.

  17. The effect of rocuronium and sugammadex on neuromuscular blockade in a child with congenital myotonic dystrophy type 1.

    PubMed

    Pickard, Amelia; Lobo, Clinton; Stoddart, Peter A

    2013-09-01

    Myotonic dystrophy type 1 (MD1) is the commonest muscular dystrophy found in adults; however, it may present in the neonatal period with hypotonia, talipes, poor feeding, and respiratory failure. Inheritance is autosomal dominant with a defect in the DMPK gene found on the long arm of chromosome 19 with variable expansion of the cytosine-thymine-guanine (CTG) triplet repeat. A 14-month-old boy with congenital MD type 1 was scheduled for percutaneous endoscopic gastrostomy (PEG) insertion, orchidopexy, and division of tongue-tie. Following induction of anesthesia, acceleromyography was used to monitor neuromuscular function. This revealed a very rapid onset of profound neuromuscular block which lasted significantly longer than would be expected in a child without MD1. Sugammadex reversed the block rapidly. The anesthetic management of children with MD1 has been well described but not the acceleromyographic monitored use of rocuronium and its subsequent reversal with the new cyclodextrin sugammadex.

  18. Ocular abnormality in myotonic dystrophy.

    PubMed

    Ginsberg, J; Hamblet, J; Menefee, M

    1978-08-01

    A 61-year-old white woman with terminal myotonic dystrophy exhibited advanced peripheral and central retinopathy. Retinal lesions were characterized by hyperpigmentation, common, though nonspecific, in myotonic dystrophy. They resemble both heredo (tapetoretinal) and idiopathic involutional degenerations but rarely cause severe visual impairment. Neither the type nor degree of retinopathy appears to correlate with other ocular features or with the stage of the underlying disease. Our histologic observations confirm and extend those previously described. Electron microscopy suggests a primary disorder of mitochondria which may also affect smooth muscle and the myocardium.

  19. Cognition and adaptive skills in myotonic dystrophy type 1: a study of 55 individuals with congenital and childhood forms.

    PubMed

    Ekström, Anne-Berit; Hakenäs-Plate, Louise; Tulinius, Már; Wentz, Elisabet

    2009-12-01

    To investigate cognitive abilities and adaptive skills in children and adolescents with myotonic dystrophy type 1 (DM1) and correlate the findings to the cytosine-thymine-guanine (CTG) repeat expansion size. Cognitive level was assessed in 55 children and adolescents with DM1 (31 males, 24 females; mean age 12y 1mo, SD 5y 1mo; range 2y 7mo-21y 5mo) divided into the following categories: severe congenital DM1 (n=19), mild congenital DM1 (n=18), and childhood DM1 (n=18). The Griffiths Mental Developmental Scale, the Wechsler Scales, and the Vineland Adaptive Behavior Scales (VABS) for adaptive skills were used for this purpose. Learning disability was found in 95% of the severe congenital group, 83% of the mild congenital group, and 89% of the childhood DM1 group. The more severe the form of DM1, the lower the full-scale IQ (FSIQ; r(s)=0.28, p=0.044). The individuals with severe congenital and childhood DM1 had a significantly higher verbal IQ than performance IQ (severe congenital: mean difference 5.7, SD 5.7, p=0.008; childhood DM1: mean difference 9.8, SD 18.0, p=0.038). CTG repeat expansion correlated negatively with FSIQ (r(s)=-0.63, p<0.006). Almost all participants showed poor results on the VABS. There was a positive relationship between cognitive level and adaptive skills in the mild congenital (r(s)=0.95, p<0.01) and childhood DM1 groups (r(s)=0.92, p<0.01). Children and adolescents with DM1 exhibit significant cognitive and adaptive problems.

  20. Cognition and Adaptive Skills in Myotonic Dystrophy Type 1: A Study of 55 Individuals with Congenital and Childhood Forms

    ERIC Educational Resources Information Center

    Ekstrom, Anne-Berit; Hakenas-Plate, Louise; Tulinius, Mar; Wentz, Elisabet

    2009-01-01

    Aims: To investigate cognitive abilities and adaptive skills in children and adolescents with myotonic dystrophy type 1 (DM1) and correlate the findings to the cytosine-thymine-guanine (CTG) repeat expansion size. Method: Cognitive level was assessed in 55 children and adolescents with DM1 (31 males, 24 females; mean age 12y 1mo, SD 5y 1mo; range…

  1. Cognition and Adaptive Skills in Myotonic Dystrophy Type 1: A Study of 55 Individuals with Congenital and Childhood Forms

    ERIC Educational Resources Information Center

    Ekstrom, Anne-Berit; Hakenas-Plate, Louise; Tulinius, Mar; Wentz, Elisabet

    2009-01-01

    Aims: To investigate cognitive abilities and adaptive skills in children and adolescents with myotonic dystrophy type 1 (DM1) and correlate the findings to the cytosine-thymine-guanine (CTG) repeat expansion size. Method: Cognitive level was assessed in 55 children and adolescents with DM1 (31 males, 24 females; mean age 12y 1mo, SD 5y 1mo; range…

  2. Cerebral and Muscle MRI Abnormalities in Myotonic Dystrophy

    PubMed Central

    Franc, Daniel T.; Muetzel, Ryan L.; Robinson, Paul R.; Rodriguez, Craig P.; Dalton, Joline C.; Naughton, Cameron E.; Mueller, Bryon A.; Wozniak, Jeffrey R.; Lim, Kelvin O.; Day, John W.

    2012-01-01

    Pathophysiological mechanisms underlying the clinically devastating CNS features of myotonic dystrophy (DM) remain more enigmatic and controversial than do the muscle abnormalities of this common form of muscular dystrophy. To better define CNS and cranial muscle changes in DM, we used quantitative volumetric and diffusion tensor MRI methods to measure cerebral and masticatory muscle differences between controls (n=5) and adults with either congenital (n=5) or adult onset (n=5) myotonic dystrophy type 1, myotonic dystrophy type 2 (n=5). Muscle volumes were diminished in DM1 and strongly correlated with reduced white matter integrity and gray matter volume. Moreover, correlation of reduced fractional anisotropy (white matter integrity) and gray matter volume in both DM1 and DM2 suggests that these abnormalities may share a common underlying pathophysiological mechanism. Further quantitative temporal and spatial characterization of these features will help delineate developmental and progressive neurological components of DM, and help determine the causative molecular and cellular mechanisms. PMID:22290140

  3. Autism spectrum conditions in myotonic dystrophy type 1: a study on 57 individuals with congenital and childhood forms.

    PubMed

    Ekström, Anne-Berit; Hakenäs-Plate, Louise; Samuelsson, Lena; Tulinius, Már; Wentz, Elisabet

    2008-09-05

    Myotonic dystrophy type 1 (DM1) is an autosomal dominant disorder, caused by an expansion of a CTG triplet repeat in the DMPK gene. The aims of the present study were to classify a cohort of children with DM1, to describe their neuropsychiatric problems and cognitive level, to estimate the size of the CTG expansion, and to correlate the molecular findings with the neuropsychiatric problems. Fifty-seven children and adolescents (26 females; 31 males) with DM1 (CTG repeats > 40) were included in the study. The following instruments were used: Autism Diagnostic Interview-Revised (ADI-R), 5-15, Griffiths Mental Development Scales, and the Wechsler Scales. Based on age at onset and presenting symptoms, the children were divided into four DM1 groups; severe congenital (n = 19), mild congenital (n = 18), childhood (n = 18), and classical DM1 (n = 2). Forty-nine percent had an autism spectrum disorder (ASD) and autistic disorder was the most common diagnosis present in 35% of the subjects. Eighty-six percent of the individuals with DM1 had mental retardation (MR), most of them moderate or severe MR. ASD was significantly correlated with the DM1 form; the more severe the form of DM1, the higher the frequency of ASD. The frequency of ASD increased with increasing CTG repeat expansions. ASD and/or other neuropsychiatric disorders such as attention deficit hyperactivity disorder, and Tourette's disorder were found in 54% of the total DM1 group. In conclusion, awareness of ASD comorbidity in DM1 is essential. Further studies are warranted to elucidate the molecular etiology causing neurodevelopmental symptoms such as ASD and MR in DM1.

  4. Apathy and hypersomnia are common features of myotonic dystrophy

    PubMed Central

    Rubinsztein, J; Rubinsztein, D; Goodburn, S; Holland, A

    1998-01-01

    OBJECTIVES—Myotonic dystrophy is a disease characterised by myotonia and muscle weakness. Psychiatric disorder and sleep problems have also been considered important features of the illness. This study investigated the extent to which apathy, major depression, and hypersomnolence were present. The objective was to clarify if the apathy reported anecdotally was a feature of CNS involvement or if this was attributable to major depression, hypersomnolence, or a consequence of chronic muscle weakness.
METHODS—These features were studied in 36 adults with non-congenital myotonic dystrophy and 13 patients with Charcot-Marie-Tooth disease. By using patients with Charcot-Marie-Tooth disease as a comparison group the aim was to control for the disabling effects of having an inherited chronic neurological disease causing muscle weakness. Standardised assessment instruments were used wherever possible to facilitate comparison with other groups reported in the medical literature.
RESULTS—There was no excess of major depression on cross sectional analysis in these patients with mild myotonic dystrophy. However, apathy was a prominent feature of myotonic dystrophy in comparison with a similarly disabled group of patients with Charcot-Marie-Tooth disease (clinician rated score; Mann Whitney U test, p=0.0005). Rates of hypersomnolence were greater in the myotonic dystrophy group, occurring in 39% of myotonic dystrophy patients, but there was no correlation with apathy.
CONCLUSION—These data suggest that apathy and hypersomnia are independent and common features of myotonic dystrophy. Apathy cannot be accounted for by clinical depression or peripheral muscle weakness and is therefore likely to reflect CNS involvement. These features of the disease impair quality of life and may be treatable.

 PMID:9576545

  5. CpG Methylation, a Parent-of-Origin Effect for Maternal-Biased Transmission of Congenital Myotonic Dystrophy.

    PubMed

    Barbé, Lise; Lanni, Stella; López-Castel, Arturo; Franck, Silvie; Spits, Claudia; Keymolen, Kathelijn; Seneca, Sara; Tomé, Stephanie; Miron, Ioana; Letourneau, Julie; Liang, Minggao; Choufani, Sanaa; Weksberg, Rosanna; Wilson, Michael D; Sedlacek, Zdenek; Gagnon, Cynthia; Musova, Zuzana; Chitayat, David; Shannon, Patrick; Mathieu, Jean; Sermon, Karen; Pearson, Christopher E

    2017-03-02

    CTG repeat expansions in DMPK cause myotonic dystrophy (DM1) with a continuum of severity and ages of onset. Congenital DM1 (CDM1), the most severe form, presents distinct clinical features, large expansions, and almost exclusive maternal transmission. The correlation between CDM1 and expansion size is not absolute, suggesting contributions of other factors. We determined CpG methylation flanking the CTG repeat in 79 blood samples from 20 CDM1-affected individuals; 21, 27, and 11 individuals with DM1 but not CDM1 (henceforth non-CDM1) with maternal, paternal, and unknown inheritance; and collections of maternally and paternally derived chorionic villus samples (7 CVSs) and human embryonic stem cells (4 hESCs). All but two CDM1-affected individuals showed high levels of methylation upstream and downstream of the repeat, greater than non-CDM1 individuals (p = 7.04958 × 10(-12)). Most non-CDM1 individuals were devoid of methylation, where one in six showed downstream methylation. Only two non-CDM1 individuals showed upstream methylation, and these were maternally derived childhood onset, suggesting a continuum of methylation with age of onset. Only maternally derived hESCs and CVSs showed upstream methylation. In contrast, paternally derived samples (27 blood samples, 3 CVSs, and 2 hESCs) never showed upstream methylation. CTG tract length did not strictly correlate with CDM1 or methylation. Thus, methylation patterns flanking the CTG repeat are stronger indicators of CDM1 than repeat size. Spermatogonia with upstream methylation may not survive due to methylation-induced reduced expression of the adjacent SIX5, thereby protecting DM1-affected fathers from having CDM1-affected children. Thus, DMPK methylation may account for the maternal bias for CDM1 transmission, larger maternal CTG expansions, age of onset, and clinical continuum, and may serve as a diagnostic indicator.

  6. [Current studies in myotonic dystrophy].

    PubMed

    Zhao, Yimeng; Ishiura, Shoichi

    2014-03-01

    Myotonic dystrophy (DM) is a genetic, progressive, multisystemic disease with muscular disorder as its primary symptom. There are two types of DM (DM1 and DM2) caused by mutations in different genes, and in Japan, DM occurs with an incidence of approximately 1 in 20,000. The pathogenic mechanism underlying the disease is RNA toxicity caused by transcripts of aberrantly elongated CTG or CCTG repeats located in the 3' untranslated region or in the intron. The current treatments for DM is limited to symptomatic care. In this review, we will discuss several new therapeutic strategies based on recent studies of RNA toxicity.

  7. Myotonic Muscular Dystrophy

    MedlinePlus

    ... are common in the type 1 form. In congenital MMD1 , which affects children from the time of birth, there can be serious impairment of cognitive functioning. These children also may have problems with speech, hearing and vision. Generally, the earlier MMD1 begins, the more profound ...

  8. Myotonic dystrophy associated with 47 XYY syndrome.

    PubMed

    Asano, A; Motomura, N; Yokota, S; Yoneda, H; Sakai, T; Tsutsumi, S

    2000-02-01

    A case of myotonic dystrophy with 47 XYY presented with tall stature and mental retardation. The patient was a 37-year-old male. In addition to grip myotonia and percussion myotonia, severe weakness and atrophy were noted in the face and the neck muscles and in the distal muscles of the four limbs. He also had diabetes mellitus, cataracts and sexual behavior abnormalities. He was found to be 47 XYY from chromosomal examinations. The combination of 47 XYY syndrome and myotonic dystrophy has not been reported previously.

  9. [Ventricular Tachycardia as a First Manifestation of Myotonic Dystrophy].

    PubMed

    Mironov, N Yu; Mironova, N A; Sokolov, S F; Mareev, Yu V; Shlevkov, N B; Saidova, M A; Stukalova, O V; Golitsyn, S P

    2015-01-01

    We report a case of bundle-branch reentrant ventricular tachycardia as a first and severe manifestation of myotonic dystrophy. Progressive cardiac conduction disturbances and cardiac arrhythmias are well-known features of myotonic dystrophy, although they are commonly found in late stage of disease in patients with established diagnosis. We review clinical manifestations, diagnostics, management, and prognostic value of cardiac involvement in myotonic dystrophy.

  10. Coincidence of neurofibromatosis and myotonic dystrophy in a kindred.

    PubMed Central

    Ichikawa, K; Crosley, C J; Culebras, A; Weitkamp, L

    1981-01-01

    Neurofibromatosis and myotonic dystrophy have occurred in ten members of a nonconsanguineous family with a high degree of concordance. The expression of neurofibromatosis is peripheral, and the expression of myotonic dystrophy has produced at least moderately severe disability. Neither disease has appeared to alter the phenotypic expression of the other when both have occurred simultaneously. Secretor typing supports the assumption that the myotonic dystrophy in this family is the commonly recognised secretor-linked entity. The segregation pattern of the two disorders in this family suggest the possibility of close linkage between the loci for neurofibromatosis and myotonic dystrophy. PMID:6787200

  11. [Maculopathy in Curschmann-Steinert myotonic dystrophy].

    PubMed

    Austermann, P; Kuba, G B; Kroll, P

    2000-11-01

    Maculopathy occurring in young patients is a challenge in differential diagnosis. Besides hereditary macular dystrophies and acquired macular degenerations, rare systemic disorders should be considered. A 36 year old female patient complained about a gradually decrease of visual acuity in both eyes and an increasing exotropia of her right eye. Visual acuity was 0.7, the orthoptical status revealed an intermittent exophoria with exclusion of the right eye. Slit lamp examination showed punctate and cristalline lens opacities. In fundus examination and fluorescein angiography clumpy pigment epithelium hypertrophies and atrophies with a reticular character could be observed. Color vision and perimetry were normal; dark visual acuity was reduced. Because of remarkable deformations of jaw and teeth, a high hairline and an uncertain step we arranged a neurological consultation. Clinical observation together with myotonic activities in electromyography and diffuse lesions in the cerebral medular corpus shown in MRT led to the diagnosis of myotonic dystrophy (Curschmann Steinert syndrome). Besides hereditary macular dystrophies and acquired macular degenerations the differential diagnosis of maculopathies in young patients also includes systemic disorders. Myotonic dystrophy (Curschmann Steinert syndrome) should be taken into account as a rare cause of a juvenile maculopathy.

  12. Long-term follow-up of motor function and muscle strength in the congenital and childhood forms of myotonic dystrophy type 1.

    PubMed

    Kroksmark, Anna-Karin; Stridh, Marie-Louise; Ekström, Anne-Berit

    2017-09-01

    The aims of this study were to explore how motor function and muscle strength change over time in the congenital and childhood forms of myotonic dystrophy type 1, further to investigate whether sex, age, disease severity or size of the mutation could explain these changes. Motor function and isometric muscle strength were evaluated at three occasions during 1999-2013 in 57 patients aged 0.7-28.9 years. Median time between first and last assessment was 11.5 years ranging from 9.6 to 13.3 years. The study shows that motor function improves during the first decade, is most pronounced during the first six years, reaches a plateau during adolescence and starts to deteriorate in the beginning of the second decade. The most predictive variables for change are age (p < 0.0001) and number of CTG-repeat expansions (p = 0.0018). Sex or disease severity grade do not predict changes in motor function. Deterioration of muscle strength is most pronounced in ankle dorsiflexors. Knowledge of development and deterioration of motor function is important for clinical decision making and for planning of interventions. This knowledge can also be of interest for patient recruitment in drug trials, since treatment effect might be easier to evaluate in the stable phases of this progressive disorder. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Early onset myotonic dystrophy in association with polyneuropathy.

    PubMed Central

    Paramesh, K; Smith, B H; Kalyanaraman, K

    1975-01-01

    A patient with early onset of myotonic dystrophy, with associated neuropathy and epilepsy, is presented. It is postulated that his disorder was inherited through a recessive, pleomorphic gene. His differential diagnosis is discussed and the literature reviewed. The clinical variability of myotonic dystrophy is stressed and the diagnostic difficulties encountered in the younger age group. Images PMID:173806

  14. A molecular protocol for diagnosing myotonic dystrophy.

    PubMed

    Guida, M; Marger, R S; Papp, A C; Snyder, P J; Sedra, M S; Kissel, J T; Mendell, J R; Prior, T W

    1995-01-01

    Myotonic dystrophy (DM) is an autosomal dominant genetic disease caused by an unstable CTG repeat sequence in the 3' untranslated region of the myotonin protein kinase gene. The CTG repeat is present 5-30 times in the normal population, whereas DM patients have CTG expansions of 50 to several thousand repeats. The age of onset of the disorder and the severity of the phenotype is roughly correlated with the size of the CTG expansion. We developed a molecular protocol for the diagnosis of DM based on an initial polymerase chain reaction screen to detect normal-sized alleles and small expansions, followed by an improved Southern protocol to detect larger expansions.

  15. Myasthenia gravis and thymoma coexisting with myotonic dystrophy type 1.

    PubMed

    Ekmekci, Ozgul; Karasoy, Hatice; Bademkiran, Fikret; Akkus, Dilek Evyapan; Yuceyar, Nur

    2014-01-01

    We describe a 34-year old man presenting with subacute generalized myasthenic symptoms. His clinical features and laboratory investigations demonstrated both myasthenia gravis and myotonic dystrophy type 1. The computerized tomography of chest revealed anterior mediastinal mass. The lymphocyte-rich thymoma was removed surgically and he received radiotherapy. Recent observations suggested that the patients with myotonic dystrophy may have an increased risk of benign and malignant tumours but its coexistence with thymoma is very rare. The risk of thymoma associated with myotonic dystrophy is unknown.

  16. Therapeutics Development in Myotonic Dystrophy Type I

    PubMed Central

    Foff, Erin Pennock; Mahadevan, Mani S.

    2011-01-01

    Myotonic dystrophy (DM1), the most common adult muscular dystrophy, is a multi-system, autosomal dominant genetic disorder caused by an expanded CTG repeat that leads to nuclear retention of a mutant RNA and subsequent RNA toxicity. Significant insights into the molecular mechanisms of RNA toxicity have led to the surprising possibility that treating DM1 is a viable prospect. In this review, we briefly present the clinical picture in DM1, and describe how the research in understanding the pathogenesis of RNA toxicity in DM1 has led to targeted approaches to therapeutic development at various steps in the pathogenesis of the disease. We discuss the promise and current limitations of each with an emphasis on RNA-based therapeutics and small molecules. We conclude with a discussion of the unmet need for clinical tools and outcome measures that are essential prerequisites to proceed in evaluating these potential therapies in clinical trials. PMID:21607985

  17. Diagnostic Odyssey of Patients with Myotonic Dystrophy

    PubMed Central

    Hilbert, James E.; Ashizawa, Tetsuo; Day, John W.; Luebbe, Elizabeth A.; Martens, William B.; McDermott, Michael P.; Tawil, Rabi; Thornton, Charles A.; Moxley, Richard T.

    2013-01-01

    The onset and symptoms of the myotonic dystrophies are diverse, complicating their diagnoses and limiting a comprehensive approach to their clinical care. This report analyzes the diagnostic delay (time from onset of first symptom to diagnosis) in a large sample of myotonic dystrophy (DM) patients enrolled in the US National Registry [679 DM type 1 (DM1) and 135 DM type 2 (DM2) patients]. Age of onset averaged 34.0 ± 14.1 years in DM2 patients compared to 26.1 ± 13.2 years in DM1 (p<0.0001). The most common initial symptom in DM2 patients was leg weakness (32.6%) compared to grip myotonia in DM1 (38.3%). Pain was reported as the first symptom in 11.1% of DM2 and 3.0% of DM1 patients (p<0.0001). Reaching the correct diagnosis in DM2 took 14 years on average (double the time compared to DM1) and a significantly higher percentage of patients underwent extended workup including electromyography, muscle biopsies, and finally genetic testing. DM patients who were index cases experienced similar diagnostic delays to non-index cases of DM. Further evaluation of how to shorten these diagnostic delays and limit their impact on burdens of disease, family planning, and symptom management is needed. PMID:23807151

  18. Electrophysiological evaluation of oropharyngeal swallowing in myotonic dystrophy

    PubMed Central

    Ertekin, C; Yuceyar, N; Aydogdu, I; Karasoy, H

    2001-01-01

    OBJECTIVE—Oropharyngeal dysphagia is a common feature of patients with myotonic dystrophy and is not usually perceived due to their emotional deficits and lack of interest. The aim was to show the existence and frequency of subclinical electrophysiological abnormalities in oropharyngeal swallowing and to clarify the mechanisms of dysphagia in myotonic dystrophy.
METHODS—Eighteen patients with myotonic dystrophy were examined for oropharyngeal phase of swallowing by clinical and electrophysiological methods. Ten patients had dysphagia whereas 11 patients had signs and symptoms reflecting CNS involvement. Four patients with myotonia congenita and 30 healthy volunteers served as controls. Laryngeal movements were detected by means of a piezoelectric sensor. EMG activities of the submental muscle (SM-EMG) and needle EMG of the cricopharyngeal muscle of the upper eosophageal sphincter (CP-EMG) were also recorded during swallowing.
RESULTS—In about 70% of the patients with myotonic dystrophy, the existence of oropharyngeal dysphagia was indicated objectively by means of the technique of "dysphagia limit" and by clinical evaluation. Duration of the swallowing reflex as defined by the laryngeal relocation time (0-2 time interval) and submental muscle excitation as a part of the swallowing reflex (A-C interval) were significantly prolonged in patients with myotonic dystrophy, especially in dysphagic patients. Triggering time of the swallowing reflex (A-0 interval) also showed significant prolongation, especially in the patients having both dysphagia and CNS involvement. During swallowing, CP muscle activity was abnormal in 40% of the patients with myotonic dystrophy.
CONCLUSION—Both myopathic weakness and myotonia encountered in oropharyngeal muscles play an important part in the oral and the pharyngeal phases of swallowing dysfunction in myotonic dystrophy. It was also suggested that CNS involvement might contribute to the delay of the triggering of the

  19. Best practice guidelines and recommendations on the molecular diagnosis of myotonic dystrophy types 1 and 2.

    PubMed

    Kamsteeg, Erik-Jan; Kress, Wolfram; Catalli, Claudio; Hertz, Jens M; Witsch-Baumgartner, Martina; Buckley, Michael F; van Engelen, Baziel G M; Schwartz, Marianne; Scheffer, Hans

    2012-12-01

    Myotonic dystrophy is an autosomal dominant, multisystem disorder that is characterized by myotonic myopathy. The symptoms and severity of myotonic dystrophy type l (DM1) ranges from severe and congenital forms, which frequently result in death because of respiratory deficiency, through to late-onset baldness and cataract. In adult patients, cardiac conduction abnormalities may occur and cause a shorter life span. In subsequent generations, the symptoms in DM1 may present at an earlier age and have a more severe course (anticipation). In myotonic dystrophy type 2 (DM2), no anticipation is described, but cardiac conduction abnormalities as in DM1 are observed and patients with DM2 additionally have muscle pain and stiffness. Both DM1 and DM2 are caused by unstable DNA repeats in untranslated regions of different genes: A (CTG)n repeat in the 3'-UTR of the DMPK gene and a (CCTG)n repeat in intron 1 of the CNBP (formerly ZNF9) gene, respectively. The length of the (CTG)n repeat expansion in DM1 correlates with disease severity and age of onset. Nevertheless, these repeat sizes have limited predictive values on individual bases. Because of the disease characteristics in DM1 and DM2, appropriate molecular testing and reporting is very important for the optimal counseling in myotonic dystrophy. Here, we describe best practice guidelines for clinical molecular genetic analysis and reporting in DM1 and DM2, including presymptomatic and prenatal testing.

  20. Myotonic dystrophy in two European grey wolves (Canis lupus).

    PubMed

    Pákozdy, A; Leschnik, M; Nell, B; Kolm, U S; Virányi, Z; Belényi, B; Molnár, M J; Bilzer, T

    2007-03-01

    Two related European Grey wolves (Canis lupus) with the history of muscle stiffness beginning at 2 weeks of age were examined in this study. Muscle tone and muscle mass were increased in both animals. Muscle stiffness was worsened by stress so that the animals fell into lateral recumbency. Blood chemistry revealed mildly increased serum creatine kinase activity. Abnormal potentials typical of myotonic discharges were recorded by electromyography. Cataract, first-degree atrioventricular (AV) block and inhomogeneous myocardial texture by ultrasound suggested extramuscular involvement. Myopathology demonstrated dystrophic signs in the muscle biopsy specimen. The presumptive diagnosis based on the in vivo findings was myotonic dystrophy. Immunochemistry of the striated muscles revealed focal absence of dystrophin 1 and beta-dystroglycan in both cases. Cardiac and ophthalmologic involvement suggested a disorder very similar to a human form of myotonic dystrophy. This is the first description of myotonic dystrophy in wolves.

  1. [Pathogenesis of myotonic dystrophy type 1].

    PubMed

    Magaña, Jonathan J; Leyva-García, Norberto; Cisneros, Bulmaro

    2009-01-01

    Myotonic dystrophy type 1 (DM1) is the most common form of muscular dystrophy in adults, affecting 1/8000 individuals. DM1 is a dominant disorder characterized by multisystemic clinical features affecting skeletal muscle, heart and the nervous and endocrine systems. DM1 is caused by an expansion of CTG trinucleotide repeats within the 3'-untranslated region (3'-UTR) of the DMPK gene. This repeat is polymorphic in normal individuals with alleles ranging from 5 to 37 in length. Repeats exceeding a threshold of approximately 50 and reaching up to a number of 4,000 result in disease. This review offers a detailed description of the scientific findings that have allowed the establishment of the molecular basis of the DM1 in the muscle and nervous systems. Currently, it is known that mutant DM1 transcript accumulates in the nucleus of muscle and neuronal cells sequestering nuclear proteins, such as splicing regulators and transcription factors to form nuclear foci that are observed under inmunofluorescence techniques. This event disturbs the expression of several muscular and neuronal genes impairing cell differentiation, which may explain the multiple symptoms of the disease. Finally, the main findings towards the development of a gene therapy for DM1 are discussed.

  2. Skin features in myotonic dystrophy type 1: an observational study.

    PubMed

    Campanati, A; Giannoni, M; Buratti, L; Cagnetti, C; Giuliodori, K; Ganzetti, G; Silvestrini, M; Provinciali, L; Offidani, A

    2015-05-01

    Poor data regarding skin involvement in Myotonic Dystrophy, also named Dystrophia Myotonica type 1, have been reported. This study aimed to investigate the prevalence and types of skin disorders in adult patients with Myotonic Dystrophy type 1. Fifty-five patients and one hundred age- and sex-matched healthy subjects were referred to a trained dermatologist for a complete skin examination to check for potential cutaneous hallmarks of disease. No difference in prevalence of preneoplastic, neoplastic, and cutaneous lesions was detected between the two groups. Among morphofunctional, proliferative and inflammatory lesions, focal hyperhidrosis (p < 0.0001), follicular hyperkeratosis (p = 0.0003), early androgenic alopecia (p = 0.01), nail pitting (p = 0.003), pedunculus fibromas (p = 0. 01), twisted hair (p = 0.01), seborrheic dermatitis (p = 0.02), macules of hyperpigmentation (p = 0.03) were significantly more frequent in patients compared with controls. In patients with Myotonic Dystrophy type 1 significant differences according to sex were found for: early androgenic alopecia, twisted hair and seborrheic dermatitis, whose prevalence was higher in males (p < 0.0001). Our preliminary results seem to rule out an increased prevalence of pre-neoplastic, and neoplastic skin lesions in Myotonic Dystrophy type 1. On the other hand, an increased prevalence of morphofunctional, inflammatory, and proliferative diseases involving adnexal structures seems to characterize adult patients with Myotonic Dystrophy type 1.

  3. Syringomyelia in myotonic dystrophy due to spinal hemangioblastoma.

    PubMed

    Mascalchi, M; Padovani, R; Taiuti, R; Quilici, N

    1998-11-01

    Syringomyelia is an uncommon, poorly understood finding in patients with myotonic dystrophy. We describe a patient with myotonic dystrophy and neck pain in whom an extensive neuroradiologic diagnostic work-up was carried out. Magnetic resonance imaging revealed a large intramedullary cavity extending from the bulbo-medullary junction to the conus medullaris. After intravenous Gadolinium-DTPA administration, an enhanced nodule was seen at T6. Spinal arteriography showed a single hypervascular nodule and slow flow perimedullary draining veins consistent with hemangioblastoma. After removal of the nodule, a partial collapse of the intramedullary cyst was observed. Intramedullary tumors can underlie syringomyelia in patients with myotonic dystrophy and have to be actively investigated with modern neuroradiologic investigations.

  4. RNA metabolism in myotonic dystrophy: patient muscle shows decreased insulin receptor RNA and protein consistent with abnormal insulin resistance.

    PubMed Central

    Morrone, A; Pegoraro, E; Angelini, C; Zammarchi, E; Marconi, G; Hoffman, E P

    1997-01-01

    Myotonic dystrophy is a dominantly inherited clinically variable multisystemic disorder, and has been found to be caused by heterozygosity for a trinucleotide repeat expansion mutation in the 3' untranslated region of a protein kinase gene (DM kinase). The mechanisms by which the expanded repeat in DNA results in a dominant biochemical defect and the varied clinical phenotype, is not known. We have recently proposed a model where disease pathogenesis may occur at the RNA level in myotonic dystrophy: the mutant DM kinase RNA with the expansion mutation may disrupt cellular RNA metabolism in some general manner, as evidenced by defects in RNA processing of the normal DM kinase gene in heterozygous patients (dominant negative RNA mutation). Here we further test this hypothesis by measuring RNA metabolism of other genes in patient muscle biopsies (nine adult onset myotonic dystrophy patients, two congenital muscular dystrophy patients, four normal controls, and four myopathic controls). We focused on the insulin receptor gene because of the documented insulin resistance of DM patients. We show that there is a significant decrease in insulin receptor RNA in both total RNA and RNA polyA+ pools relative to normal and myopathic control muscles (P < 0.002), measured relative to both dystrophin RNA and muscle sodium channel RNA. We also show reductions in insulin receptor protein. Our results reinforce the concept of a generalized RNA metabolism defect in myotonic dystrophy, and offer a possible molecular mechanism for the increased insulin resistance observed in many myotonic dystrophy patients. PMID:9120013

  5. Genetic risks for children of women with myotonic dystrophy.

    PubMed

    Koch, M C; Grimm, T; Harley, H G; Harper, P S

    1991-06-01

    In genetic counseling, the recommended risk estimate that any heterozygous woman with myotonic dystrophy (DM) will have a congenitally affected child is 3%-9%. However, after already having had such an offspring, a DM mother's risk increases to 20%-37%. The risks of 10% and 41%, respectively, calculated in this study are similar to the estimates in the literature. However, our data on clinical status of the mothers demonstrate that only women with multisystem effects of the disorder at the time of pregnancy and delivery are likely to have congenitally affected offspring. No heterozygous woman with polychromatic lens changes but no other clinically detectable multisystem involvement had a congenitally affected child. In addition, our data suggest that the chance of having a more severely affected child increases with greater severity of maternal disease. The findings of this study are relevant for genetic counseling, as the risk of having a congenitally affected child for women with classical manifestations of the disease is shown to be higher than predicted by the overall risk estimate for any heterozygous woman. We consider it appropriate to give these classically affected women risk figures which approach the recurrence risk given to mothers with congenitally affected children. However, the risk of having a congenitally affected child for heterozygous women with no multisystem involvement appears to be minimal. Our findings support the earlier proposed hypothesis of maternal metabolites acting on a heterozygous offspring. Neither genomic imprinting nor mitochondrial inheritance is able to explain the correlation between the clinical status of heterozygous mothers and that of their children.

  6. [Myotonic dystrophy with marked megacolon: report of a case].

    PubMed

    Kawai, T; Kobari, M; Ohkubo, K; Itoh, H; Kikuchi, M

    1997-11-01

    A 45-year-old woman was incidentally suspected to have megacolon. Chest X-rays showed elevated left diaphragm due to colonic gas, and the heart was deviated to the midline. Barium enema revealed marked dilation of the sigmoid colon, confirming the diagnosis of megacolon. Maximal diameter of the sigmoid colon was 23 cm, but she had no gastrointestinal symptoms. During the work up for megacolon, the presence of myotonic dystrophy was suspected. She had hatchet face, but was not bald. Muscles of the neck and extremities were slightly atrophic. There was percussion myotonia of the tongue and both hands, and grip myotonia of the hands. Laboratory examinations showed impaired glucose tolerance and low level of serum IgG. EMG showed myotonic discharges and myopathic units in the limbs. Brain CT imaging revealed a thick skull. Cases of myotonic dystrophy associated with marked megacolon are rare in Japan. Megacolon presents a high risk for ileus, volvulus, and rupture, and myotonic dystrophy is associated with a high operative and anesthesic risk. Megacolon, therefore, is an important complication to look for in the management of myotonic dystrophy.

  7. Falls and stumbles in myotonic dystrophy.

    PubMed

    Wiles, C M; Busse, M E; Sampson, C M; Rogers, M T; Fenton-May, J; van Deursen, R

    2006-03-01

    To investigate falls and risk factors in patients with myotonic dystrophy type 1 (DM1) compared with healthy volunteers. 13 sequential patients with DM1 from different kindreds were compared with 12 healthy volunteers. All subjects were evaluated using the Rivermead Mobility Index, Performance Oriented Mobility Assessment, and modified Activities Specific Balance Confidence scale. Measures of lower limb muscle strength, gait speed, and 7-day ambulatory activity monitoring were recorded. Subjects returned a weekly card detailing stumbles and falls. 11 of 13 patients (mean age 46.5 years, seven female) had 127 stumbles and 34 falls over the 13 weeks, compared with 10 of 12 healthy subjects (34.4 years, seven female) who had 26 stumbles and three falls. Patients were less active than healthy subjects but had more falls and stumbles per 5000 right steps taken (mean (SD) events, 0.21 (0.29) v 0.02 (0.02), p = 0.007). Patients who fell (n = 6) had on average a lower Rivermead Mobility score, slower self selected gait speed, and higher depression scores than those who did not. DM1 patients stumble or fall about 10 times more often than healthy volunteers. Routine inquiry about falls and stumbles is justified. A study of multidisciplinary intervention to reduce the risk of falls seems warranted.

  8. [Myotonic dystrophy as a contraindication for electroconvulsive therapy?].

    PubMed

    Wynhoven, L M L; Scherders, M J W T; van Suijlekom, J A

    2009-01-01

    A 57-year-old woman with medication-resistant major depression was referred to our clinic for electroconvulsive therapy. After an extensive evaluation of our patient's condition we concluded that in this case the comorbid myotonic dystrophy was a contraindication for the performance of electroconvulsive therapy. However, in the current Dutch Psychiatric Association guidelines this illness is not mentioned as a possible contraindication for electroconvulsive therapy. This raises the question of whether myotonic dystrophy should now be incorporated in these guidelines and makes us wonder to what extent our conclusion could have consequences for the treatment of other neuromuscular illnesses.

  9. Nifedipine in the treatment of myotonia in myotonic dystrophy.

    PubMed Central

    Grant, R; Sutton, D L; Behan, P O; Ballantyne, J P

    1987-01-01

    Abnormal calcium transport may be implicated in the membrane defect in myotonic dystrophy. A single blind crossover trial of placebo (t.i.d.), nifedipine 10 mg (t.i.d.) and nifedipine 20 mg (t.i.d.), was performed in 10 patients with myotonic dystrophy. The severity of myotonia was assessed by measuring finger extension time after maximum voluntary finger flexion. A significant improvement in myotonia, after nifedipine, was recorded by this technique and supported by a subjective improvement in 50% of patients and clinical improvement of greater than 20% in five patients. Initial grip strength and muscle fatiguability measured by grip strength ergometry were not significantly altered. Images PMID:3553433

  10. Non-Ischemic Cardiomyopathy Attributed to Adult Myotonic Dystrophy

    PubMed Central

    Park, Hyun Kyung; Park, Won Hyeong; Song, Dae-Geun; Kim, Tae Gyoon; Min, Bo Young; Lee, Keun

    2009-01-01

    In patients with myotonic dystrophy (MD), impairment of the conduction system is a common and progressive finding. However, only a few cases of MD with cardiomyopathy have been reported. Herein we report a case of MD with progressive non-ischemic cardiomyopathy and severe electrocardiographic abnormalities. PMID:19949641

  11. Psychiatric and Cognitive Phenotype of Childhood Myotonic Dystrophy Type 1

    ERIC Educational Resources Information Center

    Douniol, Marie; Jacquette, Aurelia; Cohen, David; Bodeau, Nicolas; Rachidi, Linda; Angeard, Nathalie; Cuisset, Jean-Marie; Vallee, Louis; Eymard, Bruno; Plaza, Monique; Heron, Delphine; Guile, Jean-Marc

    2012-01-01

    Aim: To investigate the psychiatric and cognitive phenotype in young individuals with the childhood form of myotonic dystrophy type 1 (DM1). Method: Twenty-eight individuals (15 females, 13 males) with childhood DM1 (mean age 17y, SD 4.6, range 7-24y) were assessed using standardized instruments and cognitive testing of general intelligence,…

  12. Psychiatric and Cognitive Phenotype of Childhood Myotonic Dystrophy Type 1

    ERIC Educational Resources Information Center

    Douniol, Marie; Jacquette, Aurelia; Cohen, David; Bodeau, Nicolas; Rachidi, Linda; Angeard, Nathalie; Cuisset, Jean-Marie; Vallee, Louis; Eymard, Bruno; Plaza, Monique; Heron, Delphine; Guile, Jean-Marc

    2012-01-01

    Aim: To investigate the psychiatric and cognitive phenotype in young individuals with the childhood form of myotonic dystrophy type 1 (DM1). Method: Twenty-eight individuals (15 females, 13 males) with childhood DM1 (mean age 17y, SD 4.6, range 7-24y) were assessed using standardized instruments and cognitive testing of general intelligence,…

  13. Misregulated alternative splicing of BIN1 is associated with T tubule alterations and muscle weakness in myotonic dystrophy.

    PubMed

    Fugier, Charlotte; Klein, Arnaud F; Hammer, Caroline; Vassilopoulos, Stéphane; Ivarsson, Ylva; Toussaint, Anne; Tosch, Valérie; Vignaud, Alban; Ferry, Arnaud; Messaddeq, Nadia; Kokunai, Yosuke; Tsuburaya, Rie; de la Grange, Pierre; Dembele, Doulaye; Francois, Virginie; Precigout, Guillaume; Boulade-Ladame, Charlotte; Hummel, Marie-Christine; Lopez de Munain, Adolfo; Sergeant, Nicolas; Laquerrière, Annie; Thibault, Christelle; Deryckere, François; Auboeuf, Didier; Garcia, Luis; Zimmermann, Pascale; Udd, Bjarne; Schoser, Benedikt; Takahashi, Masanori P; Nishino, Ichizo; Bassez, Guillaume; Laporte, Jocelyn; Furling, Denis; Charlet-Berguerand, Nicolas

    2011-06-01

    Myotonic dystrophy is the most common muscular dystrophy in adults and the first recognized example of an RNA-mediated disease. Congenital myotonic dystrophy (CDM1) and myotonic dystrophy of type 1 (DM1) or of type 2 (DM2) are caused by the expression of mutant RNAs containing expanded CUG or CCUG repeats, respectively. These mutant RNAs sequester the splicing regulator Muscleblind-like-1 (MBNL1), resulting in specific misregulation of the alternative splicing of other pre-mRNAs. We found that alternative splicing of the bridging integrator-1 (BIN1) pre-mRNA is altered in skeletal muscle samples of people with CDM1, DM1 and DM2. BIN1 is involved in tubular invaginations of membranes and is required for the biogenesis of muscle T tubules, which are specialized skeletal muscle membrane structures essential for excitation-contraction coupling. Mutations in the BIN1 gene cause centronuclear myopathy, which shares some histopathological features with myotonic dystrophy. We found that MBNL1 binds the BIN1 pre-mRNA and regulates its alternative splicing. BIN1 missplicing results in expression of an inactive form of BIN1 lacking phosphatidylinositol 5-phosphate-binding and membrane-tubulating activities. Consistent with a defect of BIN1, muscle T tubules are altered in people with myotonic dystrophy, and membrane structures are restored upon expression of the normal splicing form of BIN1 in muscle cells of such individuals. Finally, reproducing BIN1 splicing alteration in mice is sufficient to promote T tubule alterations and muscle weakness, a predominant feature of myotonic dystrophy.

  14. The brain in myotonic dystrophy 1 and 2: evidence for a predominant white matter disease.

    PubMed

    Minnerop, Martina; Weber, Bernd; Schoene-Bake, Jan-Christoph; Roeske, Sandra; Mirbach, Sandra; Anspach, Christian; Schneider-Gold, Christiane; Betz, Regina C; Helmstaedter, Christoph; Tittgemeyer, Marc; Klockgether, Thomas; Kornblum, Cornelia

    2011-12-01

    Myotonic dystrophy types 1 and 2 are progressive multisystemic disorders with potential brain involvement. We compared 22 myotonic dystrophy type 1 and 22 myotonic dystrophy type 2 clinically and neuropsychologically well-characterized patients and a corresponding healthy control group using structural brain magnetic resonance imaging at 3 T (T(1)/T(2)/diffusion-weighted). Voxel-based morphometry and diffusion tensor imaging with tract-based spatial statistics were applied for voxel-wise analysis of cerebral grey and white matter affection (P(corrected) < 0.05). We further examined the association of structural brain changes with clinical and neuropsychological data. White matter lesions rated visually were more prevalent and severe in myotonic dystrophy type 1 compared with controls, with frontal white matter most prominently affected in both disorders, and temporal lesions restricted to myotonic dystrophy type 1. Voxel-based morphometry analyses demonstrated extensive white matter involvement in all cerebral lobes, brainstem and corpus callosum in myotonic dystrophy types 1 and 2, while grey matter decrease (cortical areas, thalamus, putamen) was restricted to myotonic dystrophy type 1. Accordingly, we found more prominent white matter affection in myotonic dystrophy type 1 than myotonic dystrophy type 2 by diffusion tensor imaging. Association fibres throughout the whole brain, limbic system fibre tracts, the callosal body and projection fibres (e.g. internal/external capsules) were affected in myotonic dystrophy types 1 and 2. Central motor pathways were exclusively impaired in myotonic dystrophy type 1. We found mild executive and attentional deficits in our patients when neuropsychological tests were corrected for manual motor dysfunctioning. Regression analyses revealed associations of white matter affection with several clinical parameters in both disease entities, but not with neuropsychological performance. We showed that depressed mood and fatigue were

  15. Myotonic dystrophy type 1 (DM1): a triplet repeat expansion disorder.

    PubMed

    Kumar, Ashok; Agarwal, Sarita; Agarwal, Divya; Phadke, Shubha R

    2013-06-15

    Myotonic dystrophy is a progressive multisystem genetic disorder affecting about 1 in 8000 people worldwide. The unstable repeat expansions of (CTG)n or (CCTG)n in the DMPK and ZNF9 genes cause the two known subtypes of myotonic dystrophy: (i) myotonic dystrophy type 1 (DM1) and (ii) myotonic dystrophy type 2 (DM2) respectively. There is currently no cure but supportive management helps equally to reduce the morbidity and mortality and patients need close follow up to pay attention to their clinical problems. This review will focus on the clinical features, molecular view and genetics, diagnosis and management of DM1.

  16. The brain in myotonic dystrophy 1 and 2: evidence for a predominant white matter disease

    PubMed Central

    Weber, Bernd; Schoene-Bake, Jan-Christoph; Roeske, Sandra; Mirbach, Sandra; Anspach, Christian; Schneider-Gold, Christiane; Betz, Regina C.; Helmstaedter, Christoph; Tittgemeyer, Marc; Klockgether, Thomas; Kornblum, Cornelia

    2011-01-01

    Myotonic dystrophy types 1 and 2 are progressive multisystemic disorders with potential brain involvement. We compared 22 myotonic dystrophy type 1 and 22 myotonic dystrophy type 2 clinically and neuropsychologically well-characterized patients and a corresponding healthy control group using structural brain magnetic resonance imaging at 3 T (T1/T2/diffusion-weighted). Voxel-based morphometry and diffusion tensor imaging with tract-based spatial statistics were applied for voxel-wise analysis of cerebral grey and white matter affection (Pcorrected < 0.05). We further examined the association of structural brain changes with clinical and neuropsychological data. White matter lesions rated visually were more prevalent and severe in myotonic dystrophy type 1 compared with controls, with frontal white matter most prominently affected in both disorders, and temporal lesions restricted to myotonic dystrophy type 1. Voxel-based morphometry analyses demonstrated extensive white matter involvement in all cerebral lobes, brainstem and corpus callosum in myotonic dystrophy types 1 and 2, while grey matter decrease (cortical areas, thalamus, putamen) was restricted to myotonic dystrophy type 1. Accordingly, we found more prominent white matter affection in myotonic dystrophy type 1 than myotonic dystrophy type 2 by diffusion tensor imaging. Association fibres throughout the whole brain, limbic system fibre tracts, the callosal body and projection fibres (e.g. internal/external capsules) were affected in myotonic dystrophy types 1 and 2. Central motor pathways were exclusively impaired in myotonic dystrophy type 1. We found mild executive and attentional deficits in our patients when neuropsychological tests were corrected for manual motor dysfunctioning. Regression analyses revealed associations of white matter affection with several clinical parameters in both disease entities, but not with neuropsychological performance. We showed that depressed mood and fatigue were

  17. A Painless Retroauricular Mass in A Patient with Myotonic Dystrophy

    PubMed Central

    Som, Peter M.; Rothschild, Michael A.; Silvers, Adam R.; Norton, Karen I.

    1997-01-01

    A 16-year-old male with a history of neonatal myotonic dystrophy had a painless enlarging left retroauricular mass. Computed tomography showed an enlarged frontal sinus, thickened apparently normal bone in the anterior left clinoid process, doresum sellae, and all portions of the temporal bones. In particular, there was bone production in the left retroauricular region and along the margins of the left internal auditory canal. The left temporomandibular joint was also dislocated. This is the first case report to document the dynamic aspect of the bone changes in this dystrophy. ImagesFigure 1 PMID:17171035

  18. Warming up Improves Speech Production in Patients with Adult Onset Myotonic Dystrophy

    ERIC Educational Resources Information Center

    de Swart, B.J.M.; van Engelen, B.G.M.; Maassen, B.A.M.

    2007-01-01

    This investigation was conducted to study whether warming up decreases myotonia (muscle stiffness) during speech production or causes adverse effects due to fatigue or exhaustion caused by intensive speech activity in patients with adult onset myotonic dystrophy. Thirty patients with adult onset myotonic dystrophy (MD) and ten healthy controls…

  19. Warming up Improves Speech Production in Patients with Adult Onset Myotonic Dystrophy

    ERIC Educational Resources Information Center

    de Swart, B.J.M.; van Engelen, B.G.M.; Maassen, B.A.M.

    2007-01-01

    This investigation was conducted to study whether warming up decreases myotonia (muscle stiffness) during speech production or causes adverse effects due to fatigue or exhaustion caused by intensive speech activity in patients with adult onset myotonic dystrophy. Thirty patients with adult onset myotonic dystrophy (MD) and ten healthy controls…

  20. Vascular adrenergic receptor responses in skeletal muscle in myotonic dystrophy

    SciTech Connect

    Mechler, F.; Mastaglia, F.L.

    1981-02-01

    The pharmacological responses of vascular adrenergic receptors to intravenously administered epinephrine, phentolamine, and propranolol were assessed by measuring muscle blood flow (MBF) changes in the tibialis anterior muscle using the xenon 133 clearance technique and were compared in 8 normal subjects and 11 patients with myotonic dystrophy. In cases with advanced involvement of the muscle, the resting MBF was reduced and was not significantly altered by epinephrine before or after alpha- or beta-receptor blockade. In patients in whom the tibialis anterior muscle was normal or only minimally affected clinically, a paradoxical reduction in the epinephrine-induced increase in MBF was found after alpha blockade by phentolamine, and the epinephrine-induced MBF increase was not completely blocked by propranolol as in the normal subjects. These findings point to functional alteration in the properties of vascular adrenergic receptors in muscle in myotonic dystrophy. While this may be another manifestation of a widespread cell membrane defect in the disease, the possibility that the changes are secondary to the myotonic state cannot be excluded.

  1. Italian guidelines for molecular analysis in myotonic dystrophies.

    PubMed

    Botta, A; Bonifazi, E; Vallo, L; Gennarelli, M; Garrè, C; Salehi, L; Iraci, R; Sansone, V; Meola, G; Novelli, G

    2006-06-01

    Myotonic dystrophies, the most common form of adult muscular dystrophy, comprise at least two forms, clinically and genetically heterogeneous. Myotonic dystrophy type 1 and type 2 are both caused by unstable repetitions in untranslated gene regions: a [CTG]n expansion in the 3' region of the DMPK gene on chromosome 19q13 (DM1) and [CCTG]n tetranucleotide repeat located in the first intron of the ZNF9 gene on chromosome 3q21 (DM2). DM clinical features are caused by a gain of functions RNA mechanism in which the CUG and CCUG repeats alter nuclear functions, including alternative splicing of shared genes. Southern blot and/or polymerase chain reaction PCR-based approaches allow the detection of DM mutations in almost 100% of cases, however, the expansion size and the elevated grade of somatic instability make molecular testing for DM a diagnostic challenge. The increased use of DNA testing for DM generates many questions regarding the indications and interpretations of the test which require standardized methods, routinely available in molecular genetic laboratories. Here, we propose Guidelines for the molecular diagnosis of DM1 and DM2 approved by the Italian Ministry of Health in 2005 (Piano Nazionale Linee Guida, PNLG). Best practice for DM molecular analysis in diagnostic application, presymptomatic and prenatal testing, using direct and indirect approaches are described, with particular attention focused on ethical, legal and social issues. Overviews of materials used in the molecular diagnosis, as well as internet resources, are also included.

  2. Winged scapula in patients with myotonic dystrophy type 1.

    PubMed

    Hamano, Tadanori; Mutoh, Tatsuro; Hirayama, Mikio; Uematsu, Hidemasa; Higuchi, Itsuro; Koga, Hiroshi; Umehara, Fujio; Komai, Kiyonobu; Kuriyama, Masaru

    2012-08-01

    We report two patients with myotonic dystrophy type 1 (DM1) showing winged scapula in a single family. Genomic analysis revealed a marked expansion of CTG repeats in the 3' untranslated region; 1100 in patient 1 and 667 in patient 2. Muscle MRI revealed marked atrophy in the serratus anterior muscle in both patients. Muscle biopsy findings showed central nuclei and variations in fiber size. One of the patients showed ragged red fibers in muscles of the biceps brachii. To our knowledge, this is the first report of typical winged scapula in DM1.

  3. Epiretinal membrane: a treatable cause of visual disability in myotonic dystrophy type 1.

    PubMed

    Kersten, Hannah M; Roxburgh, Richard H; Child, Nicholas; Polkinghorne, Philip J; Frampton, Chris; Danesh-Meyer, Helen V

    2014-01-01

    A wide range of ocular abnormalities have been documented to occur in patients with myotonic dystrophy type 1. The objectives of this study were to investigate the macular and optic nerve morphology using optical coherence tomography in patients with myotonic dystrophy type 1. A total of 30 myotonic dystrophy type 1 patients and 28 controls were recruited for participation. All participants underwent a thorough ophthalmologic examination, including spectral-domain optical coherence tomography of the macula and retinal nerve fibre layer. Images were reviewed by a retinal specialist ophthalmologist, masked to the diagnosis of the participants. Average macular thickness was significantly greater in the myotonic dystrophy group compared to controls [327.3 μm vs. 308.5 μm (p < 0.001)]. Macular thickness was significantly greater (p < 0.005) in five of the nine macular regions. The increase in macular thickness was due to the increased prevalence of epiretinal membranes in the myotonic dystrophy patient group (p = 0.0002): 48.2 % of myotonic dystrophy patient eyes had evidence of epiretinal membrane, compared with 12.5 % of control eyes. Examination revealed that 56.7 % of myotonic dystrophy patients had an epiretinal membrane in at least one eye. Visual acuity was reduced due to the presence of epiretinal membrane in six patient eyes and none of the control eyes. The presence of an epiretinal membrane was significantly correlated with increasing age in the patient group. We report an increased prevalence of epiretinal membrane in the myotonic dystrophy type 1 group. This may be a previously under-recognised form of visual impairment in this group. Epiretinal membranes can be treated surgically. We suggest that, in addition to a comprehensive clinical examination, optical coherence tomography examination is implemented as part of an ophthalmological assessment for the myotonic dystrophy type 1 patient with reduced visual acuity.

  4. Segmental myofiber necrosis in myotonic dystrophy - An immunoperoxidase study of immunoglobulins in skeletal muscle.

    PubMed Central

    Silver, M. M.; Banerjee, D.; Hudson, A. J.

    1983-01-01

    Because serum immunoglobulin G levels are low in patients with myotonic dystrophy, it was hypothesized that it might be catabolized within abnormal muscle fibers. Accordingly, immunohistochemical stains for immunoglobulins were performed on muscle sections derived at biopsy or autopsy from patients with myotonic dystrophy, other forms of muscular dystrophy, nondystrophic muscle disease, or normal muscle. Positive staining for immunoglobulins was found only in necrotic segments of myofibers (in 7 of 19 dystrophic and 6 of 27 nondystrophic subjects), and it is believed that the staining was due to nonspecific diffusion. However, staining reactions distinguished between incipient necrosis and artifactual contraction bands and allowed us to study segmental myofiber necrosis, comparing its frequency in the various muscle diseases. Segmental myofiber necrosis was present in 4 of 16 cases of myotonic dystrophy. The relevance of this finding to the clinical and morphologic features of myotonic dystrophy is discussed. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:6351629

  5. Myotonic dystrophy: genetic, clinical, and molecular analysis of patients from 41 Brazilian families.

    PubMed Central

    Passos-Bueno, M R; Cerqueira, A; Vainzof, M; Marie, S K; Zatz, M

    1995-01-01

    Results of genealogical, DNA, and clinical findings in 41 families with 235 patients affected with myotonic dystrophy (DM) led to the following observations. (1) The relative proportion of affected patients among blacks is apparently lower than among whites or orientals. (2) A significant excess of males was observed. (3) The frequency of DM patients who did not reproduce was similar for males and females; however, female patients had on average 25% fewer children than male patients. (4) There was a significant intergenerational increase in the mean length of the CTG repeat which was also correlated with the severity of the phenotype. (5) No significant difference was observed in the mean size of the CTG repeat in offspring of male as compared to female transmitters. (6) With the exception of the congenital cases of maternal origin, the largest expansions were paternally inherited, but did not lead to congenital DM. Images PMID:7897620

  6. Peripheral neuropathy in patients with myotonic dystrophy type 2.

    PubMed

    Leonardis, L

    2017-05-01

    Myotonic dystrophy type 2 (dystrophia myotonica type 2-DM2) is an autosomal dominant multi-organ disorder. The involvement of the peripheral nervous system was found in 25%-45% of patients with myotonic dystrophy type 1, although limited data are available concerning polyneuropathy in patients with DM2, which was the aim of this study with a thorough presentation of the cases with peripheral neuropathy. Patients with genetically confirmed DM2 underwent motor nerve conduction studies of the median, ulnar, tibial and fibular nerves and sensory nerve conduction studies of the median (second finger), ulnar (fifth finger), radial (forearm) and sural nerves. Seventeen adult patients with DM2 participated in the study. Fifty-three percent (9/17) of our patients had abnormality of one or more attributes (latency, amplitude or conduction velocity) in two or more separate nerves. Four types of neuropathies were found: (i) predominantly axonal motor and sensory polyneuropathy, (ii) motor polyneuropathy, (iii) predominantly demyelinating motor and sensory polyneuropathy and (iv) mutilating polyneuropathy with ulcers. The most common forms are axonal motor and sensory polyneuropathy (29%) and motor neuropathy (18% of all examined patients). No correlations were found between the presence of neuropathy and age, CCTG repeats, blood glucose or HbA1C. Peripheral neuropathy is common in patients with DM2 and presents one of the multisystemic manifestations of DM2. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Noninvasive assessment of left ventricular function in myotonic muscular dystrophy.

    PubMed Central

    Venco, A; Saviotti, M; Besana, D; Finardi, G; Lanzi, G

    1978-01-01

    In order to assess left ventricular function, measurements of left ventricular internal dimension and its rate of change have been made by echocardiography in 7 patients with myotonic dystrophy and the three children of one of them, who were clinically normal but had abnormal muscle biopsies. Electrocardiograms and systolic time intervals were also recorded in all. Only one patient had signs of overt heart disease and an abnormal electrocardiogram (type B WPW). Systolic time intervals were normal in all 7 patients. Five subjects had echocardiographic abnormalities, which were of minor degree except in the patient with overt heart disease who had considerable impairment of both systolic and diastolic left ventricular function. Another patient had abnormalities of both systolic and diastolic function; systolic abnormalities occurred alone in one patient and diastolic abnormalities alone in one relative. It is concluded that patients with myotonic dystrophy and no clinical signs of heart disease may have minor abnormalities of left ventricular function as shown by echocardiography. Echocardiography is more sensitive than systolic time intervals in detecting these abnormalities; both systolic and diastolic function abnormalities, alone or together, can occur. There seems to be no relation between involvement of skeletal and cardiac muscle. PMID:718766

  8. [Nasal flaring during hypoxemia in myotonic dystrophy and duchenne muscular dystrophy].

    PubMed

    Suzuki, Mikiya; Oya, Yasushi; Murakami, Yoshitake; Ogawa, Masafumi; Kawai, Mitsuru

    2009-05-01

    We investigated the relationship between nasal flaring and SpO2 in 19 patients with Duchenne muscular dystrophy (DMD) and 26 patients with myotonic dystrophy (DM1). In DMD patients, nasal flaring was observed when SpO2 was lower than 96%, while it was not seen even at 82% of SpO2 in DM1. None of the DM1 patients could perform voluntary nasal flaring. Nasal flaring is a useful indicator of hypoxemia in DMD but not in DM1. It remains to be elucidated whether the lack of nasal flaring in DM1 patients is due to abnormal respiratory central mechanism or nasal muscle weakness.

  9. Correlates of Tumor Development in Patients with Myotonic Dystrophy

    PubMed Central

    Das, Maya; Moxley, Richard T.; Hilbert, James E.; Martens, William B.; Letren, Lisa; Greene, Mark H.; Gadalla, Shahinaz M.

    2012-01-01

    Patients with myotonic dystrophy (DM) have recently been reported to be at increased risk of tumor development, but clinical associations related to this observation are unknown. We calculated the odds ratios (ORs) and 95% confidence intervals (CI) of self-reported tumor development by patients’ demographic and clinical characteristics to evaluate factors associated with tumor development in DM patients, using data from the National Registry of Myotonic Dystrophy and Facioscapulohumeral Dystrophy Patients and Family Members. Of the 911 participants, 47.5% were male and 85.7% had DM type 1 (DM1). Compared with DM1, patients with DM type 2 (DM2) were older at Registry enrollment (median age =55 vs. 44 years, p<0.0001) and at DM diagnosis (median age= 48 vs. 30 years, p<0.0001); and more likely to be females (p=0.001). At enrollment, 95 (10.4%) DM patients reported a history of benign or malignant tumor. Tumors were associated with female gender (OR=1.9, 95% CI=1.2–3.1, p=0.007) and DM1 (OR=2.1, 95% CI=1.1–4.1, p=0.03). In a subgroup analysis of patients with blood-based DNA testing results (397 DM1, 54 DM2), repeat expansion size was not associated with tumor risk in DM1 (p=0.26) or DM2 (p=0.34). In conclusion, female gender and DM1 subtype, but not DNA repeat expansion size, were associated with increased risk of tumors in DM. Follow-up studies are warranted to determine if oncogenes associated with dystrophia myotonica-protein kinase (DMPK) are altered in DM, and to determine if repeat expansion size, as in our study, is not associated with tumor development. PMID:22619053

  10. The lack of deep reflexes in myotonic dystrophy.

    PubMed

    Messina, C; Tonali, P; Scoppetta, C

    1976-12-01

    Clinical and electrophysiological observations have been carried out on 12 patients with myotonic dystrophy. Neurological examination showed that the tendon reflexes were absent or weak in almost all cases, whereas the cutaneous reflexes were normal. Examination of both deep and superficial sensibility gave normal results. Electromyography confirmed widespread "myopathic" activity and myotonic discharges were recorded on insertion of the needle electrode and at rest. Motor and sensory conduction velocity in the ulnar nerve and motor conduction in the peroneal nerve proved to be normal. Repetitive supramaximal nerve stimulation showed in 10 cases a decrease in potential amplitude, more evident at higher frequencies of stimulation. In the 2 other cases, by contrast, an increase in amplitude was observed, and this was suggestive of a partial presynaptic block. The jaw reflex was absent in 5 cases and reduced in amplitude in the 7 other cases. The results of blink reflex investigations were normal, with the exception of 2 cases where no early response was elicited. Spinal monosynaptic reflexes were absent in 7 cases after both electrical (H reflex) and mechanical stimulation (T reflex), whereas the response to direct stimulation of nerve motor fibres (the M response) was always present, even though reduced in amplitude. Such data lead one to reject the hypothesis that the absence of deep reflexes is due to pathological change in the muscle spindles. It seems more likely that the selective atrophy of Type 1 muscle fibres, known to be involved in deep reflex responses, is responsible for the early disappearance of the tendon reflexes.

  11. Oropharyngeal dysphagia in myotonic dystrophy type 1: a systematic review.

    PubMed

    Pilz, Walmari; Baijens, Laura W J; Kremer, Bernd

    2014-06-01

    A systematic review was conducted to investigate the pathophysiology of and diagnostic procedures for oropharyngeal dysphagia in myotonic dystrophy (MD). The electronic databases Embase, PubMed, and The Cochrane Library were used. The search was limited to English, Dutch, French, German, Spanish, and Portuguese publications. Sixteen studies met the inclusion criteria. Two independent reviewers assessed the methodological quality of the included articles. Swallowing assessment tools, the corresponding protocols, the studies' outcome measurements, and main findings are summarized and presented. The body of literature on pathophysiology of swallowing in dysphagic patients with MD type 1 remains scant. The included studies are heterogeneous with respect to design and outcome measures and hence are not directly comparable. More importantly, most studies had methodological problems. These are discussed in detail and recommendations for further research on diagnostic examinations for swallowing disorders in patients with MD type 1 are provided.

  12. Delusional and psychotic disorders in juvenile myotonic dystrophy type-1.

    PubMed

    Jacobs, Delphine; Willekens, Diane; de Die-Smulders, Christine; Frijns, Jean-Pierre; Steyaert, Jean

    2017-06-01

    We investigated the clinically derived hypothesis of a relatively high incidence of delusional and psychotic disorders in adolescents with juvenile Myotonic Dystrophy type-1 (DM1). Twenty-seven subjects of age 16-25 with juvenile DM1 and their parents were invited to have a clinical psychiatric interview, and to complete an ASEBA behavior checklist (YSR, ASR, CBCL, and ABCL). We diagnosed a Delusional Disorder in 19% of our patients and a Psychotic Disorder not otherwise specified in another 19%. These two groups of patients had a significantly worse level of clinically defined general functioning. It is clinically relevant to investigate in patients with juvenile DM the symptom of delusions and the presence of a delusional and psychotic disorder, and to consider the presence of juvenile DM in youngsters presenting with such a thought disorder. These disorders compromise the general functioning of the subjects and are often to some extent treatable. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  13. Epigenetics of the myotonic dystrophy-associated DMPK gene neighborhood

    PubMed Central

    Buckley, Lauren; Lacey, Michelle; Ehrlich, Melanie

    2016-01-01

    Aim: Identify epigenetic marks in the vicinity of DMPK (linked to myotonic dystrophy, DM1) that help explain tissue-specific differences in its expression. Materials & methods: At DMPK and its flanking genes (DMWD, SIX5, BHMG1 and RSPH6A), we analyzed many epigenetic and transcription profiles from myoblasts, myotubes, skeletal muscle, heart and 30 nonmuscle samples. Results: In the DMPK gene neighborhood, muscle-associated DNA hypermethylation and hypomethylation, enhancer chromatin, and CTCF binding were seen. Myogenic DMPK hypermethylation correlated with high expression and decreased alternative promoter usage. Testis/sperm hypomethylation of BHMG1 and RSPH6A was associated with testis-specific expression. G-quadruplex (G4) motifs and sperm-specific hypomethylation were found near the DM1-linked CTG repeats within DMPK. Conclusion: Tissue-specific epigenetic features in DMPK and neighboring genes help regulate its expression. G4 motifs in DMPK DNA and RNA might contribute to DM1 pathology. PMID:26756355

  14. Forensic Considerations in Cases of Myotonic Dystrophy at Autopsy.

    PubMed

    Omond, Kimberley J; Byard, Roger W

    2017-02-07

    Myotonic dystrophy (DM) is a chronic, slowly progressive, autosomal-dominant disorder with delayed muscle relaxation after contraction, distal skeletal muscle weakness, and atrophy. It has a reduced life expectancy due predominantly to respiratory failure or sudden cardiac death. The mortality rate is approximately 7.3 times greater than the general population with a mean age at death of 53 years. Degeneration of the cardiac conduction system causes atrioventricular block, arrhythmias, and ventricular failure. A case of sudden death in a 44-year-old woman with DM type 1 is reported to demonstrate an alternative lethal mechanism. At autopsy, there was extensive infiltration of skeletal muscles with adipose tissue. The heart was structurally normal. A deep venous thrombosis of the right calf was identified with a large saddle pulmonary thromboembolus and bilateral peripheral thromboemboli. DM1-related thrombosis had most likely occurred because of the decedent's impaired mobility, possible hypercoagulable state, and serum changes from muscle necrosis.

  15. Cerebral atrophy in myotonic dystrophy: a voxel based morphometric study.

    PubMed

    Antonini, G; Mainero, C; Romano, A; Giubilei, F; Ceschin, V; Gragnani, F; Morino, S; Fiorelli, M; Soscia, F; Di Pasquale, A; Caramia, F

    2004-11-01

    Brain involvement in myotonic dystrophy type 1 (DM1) is characterised by cortical atrophy and white matter lesions. We compared the magnetic resonance imaging derived grey matter maps of 22 DM1 patients with those of matched, healthy controls using voxel based morphometry to evaluate the extension of global and regional cortical atrophy in DM1, as well as its relationships with clinical and genetic features. Patients had significantly reduced brain tissue volumes. Grey matter volume was inversely correlated with age; this inverse correlation was significantly stronger in DM1 than in controls. Neither the clinical and genetic characteristics nor white matter lesions were correlated with cortical atrophy. Grey matter atrophy was located mainly in the bilateral frontal and parietal lobes, in the bilateral middle temporal gyrus, and in the left superior temporal and occipital gyrus.

  16. A case of myotonic dystrophy with electrolyte imbalance.

    PubMed

    Ko, Weon-Jin; Kim, Kwang-Yeol; Kim, So-Mi; Hong, Seung-Jae; Lee, Sang-Hoon; Song, Ran; Yang, Hyung-In; Lee, Yeon-Ah

    2013-07-01

    Type 1 myotonic dystrophy (DM1) is an autosomal-dominant inherited disorder with a multisystem involvement, caused by an abnormal expansion of the CTG sequence of the dystrophic myotonia protein kinase (DMPK) gene. DM1 is a variable multisystem disorder with muscular and nonmuscular abnormalities. Increasingly, endocrine abnormalities, such as gonadal, pancreatic, and adrenal dysfunction are being reported. But, Electrolytes imbalance is a very rare condition in patients with DM1 yet. Herein we present a 42-yr-old Korean male of DM1 with abnormally elevated serum sodium and potassium. The patient had minimum volume of maximally concentrated urine without water loss. It was only cured by normal saline hydration. The cause of hypernatremia was considered by primary hypodipsia. Hyperkalemic conditions such as renal failure, pseudohyperkalemia, cortisol deficiency and hyperkalemic periodic paralysis were excluded. Further endocrine evaluation suggested selective hyperreninemic hypoaldosteronism as a cause of hyperkalemia.

  17. Myotonic Dystrophy Type 2: An Update on Clinical Aspects, Genetic and Pathomolecular Mechanism

    PubMed Central

    Meola, Giovanni; Cardani, Rosanna

    2015-01-01

    Abstract Myotonic dystrophy (DM) is the most common adult muscular dystrophy, characterized by autosomal dominant progressive myopathy, myotonia and multiorgan involvement. To date two distinct forms caused by similar mutations have been identified. Myotonic dystrophy type 1 (DM1, Steinert’s disease) is caused by a (CTG)n expansion in DMPK, while myotonic dystrophy type 2 (DM2) is caused by a (CCTG)n expansion in CNBP. Despite clinical and genetic similarities, DM1 and DM2 are distinct disorders. The pathogenesis of DM is explained by a common RNA gain-of-function mechanism in which the CUG and CCUG repeats alter cellular function, including alternative splicing of various genes. However additional pathogenic mechanism like changes in gene expression, modifier genes, protein translation and micro-RNA metabolism may also contribute to disease pathology and to clarify the phenotypic differences between these two types of myotonic dystrophies. This review is an update on the latest findings specific to DM2, including explanations for the differences in clinical manifestations and pathophysiology between the two forms of myotonic dystrophies. PMID:27858759

  18. Molecular genetics and genetic testing in myotonic dystrophy type 1.

    PubMed

    Savić Pavićević, Dušanka; Miladinović, Jelena; Brkušanin, Miloš; Šviković, Saša; Djurica, Svetlana; Brajušković, Goran; Romac, Stanka

    2013-01-01

    Myotonic dystrophy type 1 (DM1) is the most common adult onset muscular dystrophy, presenting as a multisystemic disorder with extremely variable clinical manifestation, from asymptomatic adults to severely affected neonates. A striking anticipation and parental-gender effect upon transmission are distinguishing genetic features in DM1 pedigrees. It is an autosomal dominant hereditary disease associated with an unstable expansion of CTG repeats in the 3'-UTR of the DMPK gene, with the number of repeats ranging from 50 to several thousand. The number of CTG repeats broadly correlates with both the age-at-onset and overall severity of the disease. Expanded DM1 alleles are characterized by a remarkable expansion-biased and gender-specific germline instability, and tissue-specific, expansion-biased, age-dependent, and individual-specific somatic instability. Mutational dynamics in male and female germline account for observed anticipation and parental-gender effect in DM1 pedigrees, while mutational dynamics in somatic tissues contribute toward the tissue-specificity and progressive nature of the disease. Genetic test is routinely used in diagnostic procedure for DM1 for symptomatic, asymptomatic, and prenatal testing, accompanied with appropriate genetic counseling and, as recommended, without predictive information about the disease course. We review molecular genetics of DM1 with focus on those issues important for genetic testing and counseling.

  19. Hypogonadism and erectile dysfunction in myotonic dystrophy type 1.

    PubMed

    Peric, Stojan; Nisic, Tanja; Milicev, Milena; Basta, Ivana; Marjanovic, Ivan; Peric, Marina; Lavrnic, Dragana; Rakocevic Stojanovic, Vidosava

    2013-10-01

    Myotonic dystrophy type 1 (DM1) is the most common form of muscular dystrophy in adults. It affects many organs and systems besides muscle. Aim of this study was to assess frequency of erectile dysfunction (ED) and hypogonadism, the correlation between them and the impact of ED on quality of life (QoL) in patients with DM1. A series of 25 men (aged from 22 to 58 years) with a diagnosis of DM1 was analyzed. Muscular Impairment Rating Scale (MIRS) was used to assess severity of muscular involvement. Erectile function was assessed using the short form of the International Index of Erectile Function test (IIEF-5). Levels of follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone were assessed. All patients completed the Serbian version of the SF-36 questionnaire as a measure of health-related QoL. ED was present in 18 (72%) of patients. Seven (28%) patients were euogonadic, 16 (64%) had compensated hypogonadism and 2 (8%) had primary hypogonadism. ED was somewhat more common in patients with hypogonadism (78% vs. 57%). Mental composite score of SF-36 was lower in patients with ED (p<0.05). Our results showed that 72% of men with DM1 had ED and hypogonadism. Studies with larger number of subjects are needed to resolve cascade of events that lays behind ED in DM1. Development of therapeutic strategies may have positive impact on QoL. Substitutive therapy with androgens may be benefitial.

  20. Cardiac involvement in myotonic muscular dystrophy (Steinert's disease): a prospective study of 25 patients

    SciTech Connect

    Perloff, J.K.; Stevenson, W.G.; Roberts, N.K.; Cabeen, W.; Weiss, J.

    1984-11-01

    The presence, degree and frequency of disorders of cardiac conduction and rhythm and of regional or global myocardial dystrophy or myotonia have not previously been studied prospectively and systematically in the same population of patients with myotonic dystrophy. Accordingly, 25 adults with classic Steinert's disease underwent electrocardiography, 24-hour ambulatory electrocardiography, vectorcardiography, chest x-rays, echocardiography, electrophysiologic studies, and technetium-99m angiography. Clinically important cardiac manifestations of myotonic dystrophy reside in specialized tissues rather than in myocardium. Involvement is relatively specific, primarily assigned to the His-Purkinje system. The cardiac muscle disorder takes the form of dystrophy rather than myotonia, and is not selective, appearing with approximately equal distribution in all 4 chambers. Myocardial dystrophy seldom results in clinically overt ventricular failure, but may be responsible for atrial and ventricular arrhythmias. Since myotonic dystrophy is genetically transmitted, a primary biochemical defect has been proposed with complete expression of the gene toward striated muscle tissue, whether skeletal or cardiac. Specialized cardiac tissue and myocardium have close, if not identical, embryologic origins, so it is not surprising that the genetic marker affects both. Cardiac involvement is therefore an integral part of myotonic dystrophy, targeting particularly the infranodal conduction system, to a lesser extent the sinus node, and still less specifically, the myocardium.

  1. Myotonic dystrophy: is a narrow focus obscuring the rest of the field?

    PubMed

    Mahadevan, Mani S

    2012-10-01

    The myotonic dystrophies (DM1 and DM2) are the paradigm for RNA toxicity in disease pathogenesis. The emphasis of this review will be on recent developments and issues in understanding the pathogenesis of DM1 and how this is driving the accelerated pace of translational and therapeutic developments. RNA toxicity in myotonic dystrophy is now associated with bi-directional antisense transcription, dysregulation of microRNAs and potentially non-ATG-mediated translation of homopolymeric toxic proteins. The role of other RNA-binding proteins beyond MBNL1 and CUGBP1, such as Staufen 1 and DDX5, are being identified and studied with respect to their role in myotonic dystrophy. New functions for MBNL1 in miR-1 biogenesis might have a clinically relevant role in myotonic dystrophy cardiac conduction defects and pathology. Advances are being made in identifying and characterizing small molecules with the potential to disrupt CUG-MBNL1 interactions. Mechanisms of RNA toxicity are moving beyond a simplistic 'foci-centric' view of DM1 pathogenesis as a spliceopathy due to MBNL1 sequestration. Therapeutic development for myotonic dystrophy is moving rapidly with the development of antisense and small molecule therapies. Clinically, significant emphasis is being placed on biomarker discovery and outcome measures as an essential prelude to clinical trials.

  2. Age of onset of RNA toxicity influences phenotypic severity: evidence from an inducible mouse model of myotonic dystrophy (DM1).

    PubMed

    Gladman, Jordan T; Mandal, Mahua; Srinivasan, Varadamurthy; Mahadevan, Mani S

    2013-01-01

    Myotonic dystrophy type 1 (DM1) is the most common muscular dystrophy in adults. It is caused by an expanded (CTG)n tract in the 3' UTR of the Dystrophia Myotonica Protein Kinase (DMPK) gene. This causes nuclear retention of the mutant mRNA into ribonuclear foci and sequestration of interacting RNA-binding proteins (such as muscleblind-like 1 (MBNL1)). More severe congenital and childhood-onset forms of the disease exist but are less understood than the adult disease, due in part to the lack of adequate animal models. To address this, we utilized transgenic mice over-expressing the DMPK 3' UTR as part of an inducible RNA transcript to model early-onset myotonic dystrophy. In mice in which transgene expression was induced during embryogenesis, we found that by two weeks after birth, mice reproduced cardinal features of myotonic dystrophy, including myotonia, cardiac conduction abnormalities, muscle weakness, histopathology and mRNA splicing defects. Notably, these defects were more severe than in adult mice induced for an equivalent period of exposure to RNA toxicity. Additionally, the utility of the model was tested by over-expressing MBNL1, a key therapeutic strategy being actively pursued for treating the disease phenotypes associated with DM1. Significantly, increased MBNL1 in skeletal muscle partially corrected myotonia and splicing defects present in these mice, demonstrating the responsiveness of the model to relevant therapeutic interventions. Furthermore, these results also represent the first murine model for early-onset DM1 and provide a tool to investigate the effects of RNA toxicity at various stages of development.

  3. Presymptomatic detection and prenatal diagnosis for myotonic dystrophy by means of linked DNA markers.

    PubMed Central

    Norman, A M; Floyd, J L; Meredith, A L; Harper, P S

    1989-01-01

    The close genetic linkage between the loci for apolipoprotein CII (ApoCII) and myotonic dystrophy makes presymptomatic detection and prenatal diagnosis feasible. We report three years' service experience of providing presymptomatic detection and prenatal diagnosis for myotonic dystrophy in 99 families. Careful clinical study of older family members remains important. The introduction of new probes (CKMM and BCL4) has helped to solve the problem of uninformativeness owing to unhelpful genotype distribution in a family. Nevertheless, informativeness cannot be guaranteed and families should be studied before pregnancy is undertaken whenever possible. Presymptomatic testing and prenatal diagnosis for myotonic dystrophy are soundly based. All affected subjects should have DNA banked for future use when other family members may require genotype information. PMID:2575669

  4. Evidence for meiotic drive at the myotonic dystrophy locus

    SciTech Connect

    Shaw, A.M.; Barnetson, R.A.; Phillips, M.F.

    1994-09-01

    Myotonic dystrophy (DM), an autosomal dominant disorder, is the most common form of adult muscular dystrophy, affecting at least 1 in 8000 of the population. It is a multisystemic disorder, primarily characterized by myotonia, muscle wasting and cataract. The molecular basis of DM is an expanded CTG repeat located within the 3{prime} untranslated region of a putative serine-threonine protein kinase on chromosome 19q13.3. DM exhibits anticipation, that is, with successive generations there is increasing disease severity and earlier age of onset. This mechanism and the fact that the origin of the disease has been attributed to one or a small number of founder chromosomes suggests that, in time, DM should die out. Meiotic drive has been described as a way in which certain alleles are transmitted to succeeding generations in preference to others: preferential transmission of large CTG alleles may account for their continued existence in the gene pool. There is evidence that a CTG allele with > 19 repeats may gradually increase in repeat number over many generations until it is sufficiently large to give a DM phenotype. We report a study of 495 transmissions from individuals heterozygous for the CTG repeat and with repeat numbers within the normal range (5-30). Alleles were simply classified as large or small relative to the other allele in an individual. Of 242 male meioses, 126 transmissions from parent to child were of the larger allele to their offspring (57.7%, p=0.014). This shows that there is strong evidence for meiotic drive favoring the transmission of the larger DM allele in unaffected individuals. Contrary to a previous report of meiotic drive in the male, we have shown that females preferentially transmit the larger DM allele. Taken together, the data suggest the occurrence of meiotic drive in both males and females in this locus.

  5. Myotonic dystrophy type 1, daytime sleepiness and REM sleep dysregulation.

    PubMed

    Dauvilliers, Yves A; Laberge, Luc

    2012-12-01

    Myotonic dystrophy type 1 (DM1), or Steinert's disease, is the most common adult-onset form of muscular dystrophy. DM1 also constitutes the neuromuscular condition with the most significant sleep disorders including excessive daytime sleepiness (EDS), central and obstructive sleep apneas, restless legs syndrome (RLS), periodic leg movements in wake (PLMW) and periodic leg movements in sleep (PLMS) as well as nocturnal and diurnal rapid eye movement (REM) sleep dysregulation. EDS is the most frequent non-muscular complaint in DM1, being present in about 70-80% of patients. Different phenotypes of sleep-related problems may mimic several sleep disorders, including idiopathic hypersomnia, narcolepsy without cataplexy, sleep apnea syndrome, and periodic leg movement disorder. Subjective and objective daytime sleepiness may be associated with the degree of muscular impairment. However, available evidence suggests that DM1-related EDS is primarily caused by a central dysfunction of sleep regulation rather than by sleep fragmentation, sleep-related respiratory events or periodic leg movements. EDS also tends to persist despite successful treatment of sleep-disordered breathing in DM1 patients. As EDS clearly impacts on physical and social functioning of DM1 patients, studies are needed to identify the best appropriate tools to identify hypersomnia, and clarify the indications for polysomnography (PSG) and multiple sleep latency test (MSLT) in DM1. In addition, further structured trials of assisted nocturnal ventilation and randomized trials of central nervous system (CNS) stimulant drugs in large samples of DM1 patients are required to optimally treat patients affected by this progressive, incurable condition.

  6. [Increasing risk of tumors in myotonic dystrophy type 1].

    PubMed

    Mohamed, Shirine; Pruna, Lelia; Kaminsky, Pierre

    2013-09-01

    Myotonic dystrophy type 1 (DM1) is characterized by an unstable expansion of a CTG repeat resulting in altered mRNA biogenesis. Benign or malignant tumours are increasingly reported. The aim of the study was to evaluate the risk of tumor in a cohort of patients DM1. We retrospectively reviewed the medical records of every DM1 patient admitted in our neuromuscular center. Diagnoses of cancer and age at diagnosis were noted. The relative risk of a selected cancer was calculated using the data of the cancer registry obtained from the French "Institut de Veille Sanitaire". A total of 109 French DM1 patients, aged 44.1±13.0 years, were studied, and 14 malignant tumours were observed, with a significant relative risk (RR) of thymoma, of gynaecologic cancers, of lung cancers. While this cohort is small, our findings nevertheless suggest an increased risk of particular cancers in DM1. The toxic effects of mutant RNA may possibly affect oncogene expression or growth factor signalling pathways in cells. Clinical practice should include cancer screening and prevention of risk factors in DM1 patients. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  7. De novo myotonic dystrophy mutation in a Nigerian kindred.

    PubMed Central

    Krahe, R; Eckhart, M; Ogunniyi, A O; Osuntokun, B O; Siciliano, M J; Ashizawa, T

    1995-01-01

    An expansion of an unstable (CTG)n trinucleotide repeat in the 3' UTR of a gene encoding a putative serine/threonine protein kinase (DMPK) on human chromosome 19q13.3 has been shown to be specific for the myotonic dystrophy (DM) disease phenotype. In addition, a single haplotype composed of nine alleles within and flanking DMPK over a physical distance of 30 kb has been shown to be in complete linkage disequilibrium with DM. This has led to two hypotheses: (1) predisposition for (CTG)n instability results from a founder effect that occurred only once or a few times in human evolution; and (2) elements within the disease haplotype may predispose the (CTG)n repeat to instability. A detailed haplotype analysis of the DM region was conducted on a Nigerian (Yoruba) DM family, the only indigenous sub-Saharan DM case reported to date. Each affected member of this family had an expanded (CTG)n repeat in one of his or her DMPK alleles. However, unlike all other DM populations studied thus far, disassociation of the (CTG)n repeat expansion from other alleles of the putative predisposing haplotype was found. We conclude that the expanded (CTG)n repeat in this family is the result of an independent mutational event. Consequently, the origin of DM is unlikely to be a single mutational event, and the hypothesis that a single ancestral haplotype predisposes to repeat expansion is not compelling. Images Figure 1 Figure 2 PMID:7726160

  8. Functioning and disability in adults with myotonic dystrophy type 1.

    PubMed

    Kierkegaard, Marie; Harms-Ringdahl, Karin; Holmqvist, Lotta Widén; Tollbäck, Anna

    2011-01-01

     To provide a comprehensive description of functioning and disability with regard to stages of disease progression in adults with myotonic dystrophy type 1 (DM1). Further to explore associations of measures of manual dexterity and of walking capacity with measures of activities of daily living (ADL) and participation in social and lifestyle activities. Seventy persons with DM1 underwent examinations, tests and answered questionnaires. Stages of disease progression were based on the muscular impairment rating scale.  Overweight, cardiac dysfunctions, respiratory restrictions, fatigue and/or low physical activity levels were found in approximately 40% of those with DM1. Over 75% had muscle impairments, and activity limitations in manual dexterity and walking. Dependence in personal and instrumental ADL was found in 16% and 39%, respectively, and participation restrictions in social and lifestyle activities in 52%. The presence of concurrent body-function impairments, activity limitations and participation restrictions was high. Significant differences were found in muscle impairment, manual dexterity, mobility, ADL and social and lifestyle activities with regard to disease progression. Cut-off values in measures of manual dexterity and walking capacity associated to functioning are proposed.  This information can be used for developing clinical practise and for health promotion for persons with DM1.

  9. Myotonic Dystrophy-1 Complicated by Factor-V (Leiden) Mutation

    PubMed Central

    Finsterer, Josef; Stöllberger, Claudia

    2015-01-01

    Objectives. Presence of a factor-V Leiden mutation in a patient with myotonic dystrophy type 1 (DM1) has been reported only once. Here we report the second DM1 patient carrying a factor-V mutation who died from long-term complications of this mutation. Case Report. A 66-year-old DM1 patient with multi-organ-disorder syndrome developed a first deep venous thrombosis (DVT) and consecutive pulmonary embolism (PE) at age 50 y. Acetyl-salicylic acid was given. One year later he experienced a second DVT; that is why phenprocoumon was started. Despite anticoagulation, he experienced a third DVT bilaterally and a second PE bilaterally at 61 y; that is why a vena cava filter was additionally deployed. Despite therapeutic anticoagulation, he experienced a vena cava filter thrombosis at age 62 y. Genetic workup revealed a heterozygous factor-V mutation in addition to a CTG-repeat expansion of 500. As a consequence of PE he developed chronic obstructive pulmonary disease and experienced recurrent pulmonary infections, which were lastly responsible for decease at age 66 y despite intensive care measures. Conclusion. The heterozygous Leiden mutation may severely affect DM1 patients to such a degree that they die from its complications. If DM1 patients present with unusual manifestations, search for causes other than a CTG-repeat expansion is indicated. PMID:25918532

  10. Synaptic protein dysregulation in myotonic dystrophy type 1

    PubMed Central

    Hernández-Hernández, Oscar; Sicot, Géraldine; Dinca, Diana M.; Huguet, Aline; Nicole, Annie; Buée, Luc; Munnich, Arnold; Sergeant, Nicolas; Gourdon, Geneviève; Gomes-Pereira, Mário

    2013-01-01

    The toxicity of expanded transcripts in myotonic dystrophy type 1 (DM1) is mainly mediated by the disruption of alternative splicing. However, the detailed disease mechanisms in the central nervous system (CNS) have not been fully elucidated. In our recent study, we demonstrated that the accumulation of mutant transcripts in the CNS of a mouse model of DM1 disturbs splicing in a region-specific manner. We now discuss that the spatial- and temporal-regulated expression of splicing factors may contribute to the region-specific spliceopathy in DM1 brains. In the search for disease mechanisms operating in the CNS, we found that the expression of expanded CUG-containing RNA affects the expression and phosphorylation of synaptic vesicle proteins, possibly contributing to DM1 neurological phenotypes. Although mediated by splicing regulators with a described role in DM1, the misregulation of synaptic proteins was not associated with missplicing of their coding transcripts, supporting the view that DM1 mechanisms in the CNS have also far-reaching implications beyond the disruption of a splicing program. PMID:25003003

  11. In vitro mapping of Myotonic Dystrophy (DM) gene promoter

    SciTech Connect

    Storbeck, C.J.; Sabourin, L.; Baird, S.

    1994-09-01

    The Myotonic Dystrophy Kinase (DMK) gene has been cloned and shared homology to serine/threonine protein kinases. Overexpression of this gene in stably transfected mouse myoblasts has been shown to inhibit fusion into myotubes while myoblasts stably transfected with an antisense construct show increased fusion potential. These experiments, along with data showing that the DM gene is highly expressed in muscle have highlighted the possibility of DMK being involved in myogenesis. The promoter region of the DM gene lacks a consensus TATA box and CAAT box, but harbours numerous transcription binding sites. Clones containing extended 5{prime} upstream sequences (UPS) of DMK only weakly drive the reporter gene chloramphenicol acetyl transferase (CAT) when transfected into C2C12 mouse myoblasts. However, four E-boxes are present in the first intron of the DM gene and transient assays show increased expression of the CAT gene when the first intron is present downstream of these 5{prime} UPS in an orientation dependent manner. Comparison between mouse and human sequence reveals that the regions in the first intron where the E-boxes are located are highly conserved. The mapping of the promoter and the importance of the first intron in the control of DMK expression will be presented.

  12. Compound loss of muscleblind-like function in myotonic dystrophy.

    PubMed

    Lee, Kuang-Yung; Li, Moyi; Manchanda, Mini; Batra, Ranjan; Charizanis, Konstantinos; Mohan, Apoorva; Warren, Sonisha A; Chamberlain, Christopher M; Finn, Dustin; Hong, Hannah; Ashraf, Hassan; Kasahara, Hideko; Ranum, Laura P W; Swanson, Maurice S

    2013-12-01

    Myotonic dystrophy (DM) is a multi-systemic disease that impacts cardiac and skeletal muscle as well as the central nervous system (CNS). DM is unusual because it is an RNA-mediated disorder due to the expression of toxic microsatellite expansion RNAs that alter the activities of RNA processing factors, including the muscleblind-like (MBNL) proteins. While these mutant RNAs inhibit MBNL1 splicing activity in heart and skeletal muscles, Mbnl1 knockout mice fail to recapitulate the full-range of DM symptoms in these tissues. Here, we generate mouse Mbnl compound knockouts to test the hypothesis that Mbnl2 functionally compensates for Mbnl1 loss. Although Mbnl1(-/-) ; Mbnl2(-/-) double knockouts (DKOs) are embryonic lethal, Mbnl1(-/-) ; Mbnl2(+/-) mice are viable but develop cardinal features of DM muscle disease including reduced lifespan, heart conduction block, severe myotonia and progressive skeletal muscle weakness. Mbnl2 protein levels are elevated in Mbnl1(-/-) knockouts where Mbnl2 targets Mbnl1-regulated exons. These findings support the hypothesis that compound loss of MBNL function is a critical event in DM pathogenesis and provide novel mouse models to investigate additional pathways disrupted in this RNA-mediated disease.

  13. Targeting nuclear RNA for in vivo correction of myotonic dystrophy

    PubMed Central

    Wheeler, Thurman M.; Leger, Andrew J.; Pandey, Sanjay K.; MacLeod, A. Robert; Nakamori, Masayuki; Cheng, Seng H.; Wentworth, Bruce M.; Bennett, C. Frank; Thornton, Charles A.

    2014-01-01

    Antisense oligonucleotides (ASOs) hold promise for gene-specific knockdown in diseases that involve RNA or protein gain-of-function. In the hereditary degenerative disease myotonic dystrophy type 1 (DM1), transcripts from the mutant allele contain an expanded CUG repeat1–3 and are retained in the nucleus4, 5. The mutant RNA exerts a toxic gain-of-function6, making it an appropriate target for therapeutic ASOs. However, despite improvements in ASO chemistry and design, systemic use of ASOs is limited because uptake in many tissues, including skeletal and cardiac muscle, is not sufficient to silence target mRNAs7, 8. Here we show that nuclear-retained transcripts containing expanded CUG (CUGexp) repeats are extraordinarily sensitive to antisense silencing. In a transgenic mouse model of DM1, systemic administration of ASOs caused a rapid knockdown of CUGexp RNA in skeletal muscle, correcting the physiological, histopathologic, and transcriptomic features of the disease. The effect was sustained for up to one year after treatment was discontinued. Systemically administered ASOs were also effective for muscle knockdown of Malat-1, a long noncoding RNA (lncRNA) that is retained in the nucleus9. These results provide a general strategy to correct RNA gain-of-function and modulate the expression of expanded repeats, lncRNAs, and other transcripts with prolonged nuclear residence. PMID:22859208

  14. Altered nuclear structure in myotonic dystrophy type 1-derived fibroblasts.

    PubMed

    Rodríguez, R; Hernández-Hernández, O; Magaña, J J; González-Ramírez, R; García-López, E S; Cisneros, B

    2015-02-01

    Myotonic dystrophy type 1 (DM1) is a multisystem genetic disorder caused by a triplet nucleotide repeat expansion in the 3' untranslated region of the Dystrophia Myotonica-Protein Kinase (DMPK) gene. DMPK gene transcripts containing CUG expanded repeats accumulate in nuclear foci and ultimately cause altered splicing/gene expression of numerous secondary genes. The study of primary cell cultures derived from patients with DM1 has allowed the identification and further characterization of molecular mechanisms underlying the pathology in the natural context of the disease. In this study we show for the first time impaired nuclear structure in fibroblasts of DM1 patients. DM1-derived fibroblasts exhibited altered localization of the nuclear envelope (NE) proteins emerin and lamins A/C and B1 with concomitant increased size and altered shape of nuclei. Abnormal NE organization is more common in DM1 fibroblasts containing abundant nuclear foci, implying expression of the expanded RNA as determinant of nuclear defects. That transient expression of the DMPK 3' UTR containing 960 CTG but not with the 3' UTR lacking CTG repeats is sufficient to generate NE disruption in normal fibroblasts confirms the direct impact of mutant RNA on NE architecture. We also evidence nucleoli distortion in DM1 fibroblasts by immunostaining of the nucleolar protein fibrillarin, implying a broader effect of the mutant RNA on nuclear structure. In summary, these findings reveal that NE disruption, a hallmark of laminopathy disorders, is a novel characteristic of DM1.

  15. Development of a Genomic DNA Reference Material Panel for Myotonic Dystrophy Type 1 (DM1) Genetic Testing

    PubMed Central

    Kalman, Lisa; Tarleton, Jack; Hitch, Monica; Hegde, Madhuri; Hjelm, Nick; Berry-Kravis, Elizabeth; Zhou, Lili; Hilbert, James E.; Luebbe, Elizabeth A.; Moxley, Richard T.; Toji, Lorraine

    2014-01-01

    Myotonic dystrophy type 1 (DM1) is caused by expansion of a CTG triplet repeat in the 3′ untranslated region of the DMPK gene that encodes a serine-threonine kinase. Patients with larger repeats tend to have a more severe phenotype. Clinical laboratories require reference and quality control materials for DM1 diagnostic and carrier genetic testing. Well-characterized reference materials are not available. To address this need, the Centers for Disease Control and Prevention-based Genetic Testing Reference Material Coordination Program, in collaboration with members of the genetic testing community, the National Registry of Myotonic Dystrophy and Facioscapulohumeral Muscular Dystrophy Patients and Family Members, and the Coriell Cell Repositories, has established and characterized cell lines from patients with DM1 to create a reference material panel. The CTG repeats in genomic DNA samples from 10 DM1 cell lines were characterized in three clinical genetic testing laboratories using PCR and Southern blot analysis. DMPK alleles in the samples cover four of five DM1 clinical categories: normal (5 to 34 repeats), mild (50 to 100 repeats), classical (101 to 1000 repeats), and congenital (>1000 repeats). We did not identify or establish Coriell cell lines in the premutation range (35 to 49 repeats). These samples are publicly available for quality control, proficiency testing, test development, and research and should help improve the accuracy of DM1 testing. PMID:23680132

  16. Development of a genomic DNA reference material panel for myotonic dystrophy type 1 (DM1) genetic testing.

    PubMed

    Kalman, Lisa; Tarleton, Jack; Hitch, Monica; Hegde, Madhuri; Hjelm, Nick; Berry-Kravis, Elizabeth; Zhou, Lili; Hilbert, James E; Luebbe, Elizabeth A; Moxley, Richard T; Toji, Lorraine

    2013-07-01

    Myotonic dystrophy type 1 (DM1) is caused by expansion of a CTG triplet repeat in the 3' untranslated region of the DMPK gene that encodes a serine-threonine kinase. Patients with larger repeats tend to have a more severe phenotype. Clinical laboratories require reference and quality control materials for DM1 diagnostic and carrier genetic testing. Well-characterized reference materials are not available. To address this need, the Centers for Disease Control and Prevention-based Genetic Testing Reference Material Coordination Program, in collaboration with members of the genetic testing community, the National Registry of Myotonic Dystrophy and Facioscapulohumeral Muscular Dystrophy Patients and Family Members, and the Coriell Cell Repositories, has established and characterized cell lines from patients with DM1 to create a reference material panel. The CTG repeats in genomic DNA samples from 10 DM1 cell lines were characterized in three clinical genetic testing laboratories using PCR and Southern blot analysis. DMPK alleles in the samples cover four of five DM1 clinical categories: normal (5 to 34 repeats), mild (50 to 100 repeats), classical (101 to 1000 repeats), and congenital (>1000 repeats). We did not identify or establish Coriell cell lines in the premutation range (35 to 49 repeats). These samples are publicly available for quality control, proficiency testing, test development, and research and should help improve the accuracy of DM1 testing.

  17. Selective disappearance of medial back muscles in a case of myotonic dystrophy type 1.

    PubMed

    Morihara, Ryuta; Hishikawa, Nozomi; Yamashita, Toru; Deguchi, Kentaro; Kurata, Tomoko; Abe, Koji

    2015-01-01

    Here, we report a unique case of late-onset myotonic dystrophy type 1 in a 64-year-old woman, with selective disappearance of the medial lower back muscles. We compared the clinical features of this patient with those of a cohort of 29 patients with myotonic dystrophy type 1 to clarify the correlation between clinical features and lower back muscle atrophy. After classification into three subgroups according to muscle atrophy pattern, medial muscle atrophy was present in 17.2% of the patients. Affected patients were older at onset than non-affected patients, and limb muscle power and respiratory function decreased with atrophy progression.

  18. Brain imaging in myotonic dystrophy type 1: A systematic review.

    PubMed

    Okkersen, Kees; Monckton, Darren G; Le, Nhu; Tuladhar, Anil M; Raaphorst, Joost; van Engelen, Baziel G M

    2017-08-29

    To systematically review brain imaging studies in myotonic dystrophy type 1 (DM1). We searched Embase (index period 1974-2016) and MEDLINE (index period 1946-2016) for studies in patients with DM1 using MRI, magnetic resonance spectroscopy (MRS), functional MRI (fMRI), CT, ultrasound, PET, or SPECT. From 81 studies, we extracted clinical characteristics, primary outcomes, clinical-genetic correlations, and information on potential risk of bias. Results were summarized and pooled prevalence of imaging abnormalities was calculated, where possible. In DM1, various imaging changes are widely dispersed throughout the brain, with apparently little anatomical specificity. We found general atrophy and widespread gray matter volume reductions in all 4 cortical lobes, the basal ganglia, and cerebellum. The pooled prevalence of white matter hyperintensities is 70% (95% CI 64-77), compared with 6% (95% CI 3-12) in unaffected controls. DTI shows increased mean diffusivity in all 4 lobes and reduced fractional anisotropy in virtually all major association, projection, and commissural white matter tracts. Functional studies demonstrate reduced glucose uptake and cerebral perfusion in frontal, parietal, and temporal lobes, and abnormal fMRI connectivity patterns that correlate with personality traits. There is significant between-study heterogeneity in terms of imaging methods, which together with the established clinical variability of DM1 may explain divergent results. Longitudinal studies are remarkably scarce. DM1 brains show widespread white and gray matter involvement throughout the brain, which is supported by abnormal resting-state network, PET/SPECT, and MRS parameters. Longitudinal studies evaluating spatiotemporal imaging changes are essential. © 2017 American Academy of Neurology.

  19. Psychosocial impact of predictive testing for myotonic dystrophy type 1.

    PubMed

    Prévost, Claude; Veillette, Suzanne; Perron, Michel; Laberge, Claude; Tremblay, Carmen; Auclair, Julie; Villeneuve, Josée; Tremblay, Marc; Mathieu, Jean

    2004-04-01

    In the Saguenay-Lac-Saint-Jean region (Quebec, Canada), a predictive DNA-testing program for myotonic dystrophy type 1 (DM1) has been available as a clinical service since 1988. From 1 to 12 years (median, 5 years) after receiving predictive testing, a total of 308 participants (44 carriers and 264 non-carriers) answered a questionnaire to determine the psychosocial impact of this genetic testing. The main reasons for wanting to be tested were to learn if children are at risk for DM1 or for reproductive decision making (75%) and to relieve the uncertainty for themselves (17%). The majority of participants (96.1%) remembered correctly their test result. At the time of the survey, the perception of the general well-being, the psychological distress (Psychiatric Symptom Index), and the self-esteem (Rosenberg Self-Esteem Scale) were similar in carriers, in non-carriers, and in the reference (Quebec) population. When participants indicated a change in different aspects of their lives following predictive testing, it was perceived as a change for the better by non-carriers and as a change for the worse by carriers. Nevertheless, for a majority of carriers and of non-carriers, the test result did not bring changes in their lives. All respondents believed that predictive testing should be available for the at-risk population and the vast majority of carrier and of non-carriers would recommend the use of predictive testing to their family members. Predictive testing for individuals at-risk of DM1 can be offered safely within a well-organized clinical and genetic counseling program that includes careful pre-test counseling, pre-test clinical assessment, post-test psychological support, and follow-up for those identified as carriers. Copyright 2003 Wiley-Liss, Inc.

  20. A Molecular Signature of Myalgia in Myotonic Dystrophy 2.

    PubMed

    Moshourab, Rabih; Palada, Vinko; Grunwald, Stefanie; Grieben, Ulrike; Lewin, Gary R; Spuler, Simone

    2016-05-01

    Chronic muscle pain affects close to 20% of the population and is a major health burden. The underlying mechanisms of muscle pain are difficult to investigate as pain presents in patients with very diverse histories. Treatment options are therefore limited and not tailored to underlying mechanisms. To gain insight into the pathophysiology of myalgia we investigated a homogeneous group of patients suffering from myotonic dystrophy type 2 (DM2), a monogenic disorder presenting with myalgia in at least 50% of affected patients. After IRB approval we performed an observational cross-sectional cohort study and recruited 42 patients with genetically confirmed DM2 plus 20 healthy age and gender matched control subjects. All participants were subjected to an extensive sensory-testing protocol. In addition, RNA sequencing was performed from 12 muscle biopsy specimens obtained from DM2 patients. Clinical sensory testing as well as RNA sequencing clearly separated DM2 myalgic from non-myalgia patients and also from healthy controls. In particular pressure pain thresholds were significantly lowered for all muscles tested in myalgic DM2 patients but were not significantly different between non-myalgic patients and healthy controls. The expression of fourteen muscle expressed genes in myalgic patients was significantly up or down-regulated in myalgic compared to non-myalgic DM2 patients. Our data support the idea that molecular changes in the muscles of DM2 patients are associated with muscle pain. Further studies should address whether muscle-specific molecular pathways play a significant role in myalgia in order to facilitate the development of mechanism-based therapeutic strategies to treat musculoskeletal pain. This study was funded by the German Research Society (DFG, GK1631), KAP programme of Charité Universitätsmedizin Berlin and Max Delbrück Center for Molecular Medicine. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Abnormal Splicing of NEDD4 in Myotonic Dystrophy Type 2

    PubMed Central

    Screen, Mark; Jonson, Per Harald; Raheem, Olayinka; Palmio, Johanna; Laaksonen, Reijo; Lehtimäki, Terho; Sirito, Mario; Krahe, Ralf; Hackman, Peter; Udd, Bjarne

    2015-01-01

    Myotonic dystrophy type 2 (DM2) is a multisystemic disorder caused by a (CCTG)n repeat expansion in intron 1 of CNBP. Transcription of the repeats causes a toxic RNA gain of function involving their accumulation in ribonuclear foci. This leads to sequestration of splicing factors and alters pre-mRNA splicing in a range of downstream effector genes, which is thought to contribute to the diverse DM2 clinical features. Hyperlipidemia is frequent in DM2 patients, but the treatment is problematic because of an increased risk of statin-induced adverse reactions. Hypothesizing that shared pathways lead to the increased risk, we compared the skeletal muscle expression profiles of DM2 patients and controls with patients with hyperlipidemia on statin therapy. Neural precursor cell expressed, developmentally downregulated-4 (NEDD4), an ubiquitin ligase, was one of the dysregulated genes identified in DM2 patients and patients with statin-treated hyperlipidemia. In DM2 muscle, NEDD4 mRNA was abnormally spliced, leading to aberrant NEDD4 proteins. NEDD4 was down-regulated in persons taking statins, and simvastatin treatment of C2C12 cells suppressed NEDD4 transcription. Phosphatase and tensin homologue (PTEN), an established NEDD4 target, was increased and accumulated in highly atrophic DM2 muscle fibers. PTEN ubiquitination was reduced in DM2 myofibers, suggesting that the NEDD4-PTEN pathway is dysregulated in DM2 skeletal muscle. Thus, this pathway may contribute to the increased risk of statin-adverse reactions in patients with DM2. PMID:24907641

  2. Muscle wasting in myotonic dystrophies: a model of premature aging.

    PubMed

    Mateos-Aierdi, Alba Judith; Goicoechea, Maria; Aiastui, Ana; Fernández-Torrón, Roberto; Garcia-Puga, Mikel; Matheu, Ander; López de Munain, Adolfo

    2015-01-01

    Myotonic dystrophy type 1 (DM1 or Steinert's disease) and type 2 (DM2) are multisystem disorders of genetic origin. Progressive muscular weakness, atrophy and myotonia are the most prominent neuromuscular features of these diseases, while other clinical manifestations such as cardiomyopathy, insulin resistance and cataracts are also common. From a clinical perspective, most DM symptoms are interpreted as a result of an accelerated aging (cataracts, muscular weakness and atrophy, cognitive decline, metabolic dysfunction, etc.), including an increased risk of developing tumors. From this point of view, DM1 could be described as a progeroid syndrome since a notable age-dependent dysfunction of all systems occurs. The underlying molecular disorder in DM1 consists of the existence of a pathological (CTG) triplet expansion in the 3' untranslated region (UTR) of the Dystrophia Myotonica Protein Kinase (DMPK) gene, whereas (CCTG)n repeats in the first intron of the Cellular Nucleic acid Binding Protein/Zinc Finger Protein 9 (CNBP/ZNF9) gene cause DM2. The expansions are transcribed into (CUG)n and (CCUG)n-containing RNA, respectively, which form secondary structures and sequester RNA-binding proteins, such as the splicing factor muscleblind-like protein (MBNL), forming nuclear aggregates known as foci. Other splicing factors, such as CUGBP, are also disrupted, leading to a spliceopathy of a large number of downstream genes linked to the clinical features of these diseases. Skeletal muscle regeneration relies on muscle progenitor cells, known as satellite cells, which are activated after muscle damage, and which proliferate and differentiate to muscle cells, thus regenerating the damaged tissue. Satellite cell dysfunction seems to be a common feature of both age-dependent muscle degeneration (sarcopenia) and muscle wasting in DM and other muscle degenerative diseases. This review aims to describe the cellular, molecular and macrostructural processes involved in the muscular

  3. Myotonic dystrophy CTG expansion affects synaptic vesicle proteins, neurotransmission and mouse behaviour

    PubMed Central

    Hernández-Hernández, Oscar; Guiraud-Dogan, Céline; Sicot, Géraldine; Huguet, Aline; Luilier, Sabrina; Steidl, Esther; Saenger, Stefanie; Marciniak, Elodie; Obriot, Hélène; Chevarin, Caroline; Nicole, Annie; Revillod, Lucile; Charizanis, Konstantinos; Lee, Kuang-Yung; Suzuki, Yasuhiro; Kimura, Takashi; Matsuura, Tohru; Cisneros, Bulmaro; Swanson, Maurice S.; Trovero, Fabrice; Buisson, Bruno; Bizot, Jean-Charles; Hamon, Michel; Humez, Sandrine; Bassez, Guillaume; Metzger, Friedrich; Buée, Luc; Munnich, Arnold; Sergeant, Nicolas; Gourdon, Geneviève

    2013-01-01

    Myotonic dystrophy type 1 is a complex multisystemic inherited disorder, which displays multiple debilitating neurological manifestations. Despite recent progress in the understanding of the molecular pathogenesis of myotonic dystrophy type 1 in skeletal muscle and heart, the pathways affected in the central nervous system are largely unknown. To address this question, we studied the only transgenic mouse line expressing CTG trinucleotide repeats in the central nervous system. These mice recreate molecular features of RNA toxicity, such as RNA foci accumulation and missplicing. They exhibit relevant behavioural and cognitive phenotypes, deficits in short-term synaptic plasticity, as well as changes in neurochemical levels. In the search for disease intermediates affected by disease mutation, a global proteomics approach revealed RAB3A upregulation and synapsin I hyperphosphorylation in the central nervous system of transgenic mice, transfected cells and post-mortem brains of patients with myotonic dystrophy type 1. These protein defects were associated with electrophysiological and behavioural deficits in mice and altered spontaneous neurosecretion in cell culture. Taking advantage of a relevant transgenic mouse of a complex human disease, we found a novel connection between physiological phenotypes and synaptic protein dysregulation, indicative of synaptic dysfunction in myotonic dystrophy type 1 brain pathology. PMID:23404338

  4. Myotonic dystrophy CTG expansion affects synaptic vesicle proteins, neurotransmission and mouse behaviour.

    PubMed

    Hernández-Hernández, Oscar; Guiraud-Dogan, Céline; Sicot, Géraldine; Huguet, Aline; Luilier, Sabrina; Steidl, Esther; Saenger, Stefanie; Marciniak, Elodie; Obriot, Hélène; Chevarin, Caroline; Nicole, Annie; Revillod, Lucile; Charizanis, Konstantinos; Lee, Kuang-Yung; Suzuki, Yasuhiro; Kimura, Takashi; Matsuura, Tohru; Cisneros, Bulmaro; Swanson, Maurice S; Trovero, Fabrice; Buisson, Bruno; Bizot, Jean-Charles; Hamon, Michel; Humez, Sandrine; Bassez, Guillaume; Metzger, Friedrich; Buée, Luc; Munnich, Arnold; Sergeant, Nicolas; Gourdon, Geneviève; Gomes-Pereira, Mário

    2013-03-01

    Myotonic dystrophy type 1 is a complex multisystemic inherited disorder, which displays multiple debilitating neurological manifestations. Despite recent progress in the understanding of the molecular pathogenesis of myotonic dystrophy type 1 in skeletal muscle and heart, the pathways affected in the central nervous system are largely unknown. To address this question, we studied the only transgenic mouse line expressing CTG trinucleotide repeats in the central nervous system. These mice recreate molecular features of RNA toxicity, such as RNA foci accumulation and missplicing. They exhibit relevant behavioural and cognitive phenotypes, deficits in short-term synaptic plasticity, as well as changes in neurochemical levels. In the search for disease intermediates affected by disease mutation, a global proteomics approach revealed RAB3A upregulation and synapsin I hyperphosphorylation in the central nervous system of transgenic mice, transfected cells and post-mortem brains of patients with myotonic dystrophy type 1. These protein defects were associated with electrophysiological and behavioural deficits in mice and altered spontaneous neurosecretion in cell culture. Taking advantage of a relevant transgenic mouse of a complex human disease, we found a novel connection between physiological phenotypes and synaptic protein dysregulation, indicative of synaptic dysfunction in myotonic dystrophy type 1 brain pathology.

  5. [A genetic systemic disease: clinical description of type 1 myotonic dystrophy in adults].

    PubMed

    Kaminsky, P; Pruna, L

    2012-09-01

    Type 1 myotonic dystrophy is an autosomal dominant inherited disorder related to the expansion of a trinucleotide (CTG) repeat in the exon 15 in the 3'-untranslated region of the myotonic dystrophy protein kinase (DMPK) gene. Mutant transcripts containing an expanded CUG repeat are retained in nuclear foci and cause numerous dysfunctions by interfering with biogenesis of other mRNAs. Prominent clinical features are progressive muscular weakness and myotonia, which affect skeletal muscles but also white muscles leading to digestive, urinary and obstetrical disorders. Functional prognosis correlates with motor handicap and vital prognosis is linked to cardiac rhythm disturbances and conduction defects due to progressive subendocardial fibrosis, and to complex respiratory dysfunctions, which associate restrictive lung disease, involvement of the central inspiratory pathway, and sleep apnea. Other clinical features are lens opacity, glucose intolerance, metabolic syndrome, several endocrine disorders (gonadal deficiency, hyperparathydoidism), or immunoglobulin deficiency due to immunoglobulin G hypercatabolism. Life expectancy is reduced in myotonic dystrophy, and death is mainly caused by respiratory complications, but also by cardiac arrhythmias. Moreover, an abnormal incidence of tumors has been reported. Therefore, myotonic dystrophy does not only concern neurologists but a multidisciplinary approach is necessary, including at least pneumologist, cardiologist, and physiotherapist. General internists should also be implicated, not only in the initial diagnosis step, but also in the diagnosis of complications and their treatments.

  6. Does quantitative EMG differ myotonic dystrophy type 2 and type 1?

    PubMed

    Szmidt-Salkowska, Elzbieta; Gawel, Malgorzata; Lusakowska, Anna; Nojszewska, Monika; Lipowska, Marta; Sulek, Anna; Krysa, Wioletta; Rajkiewicz, Marta; Seroka, Andrzej; Kaminska, Anna M

    2014-10-01

    Genetic testing is considered the only reliable diagnostic approach in myotonic dystrophy. However it has recently been reported that a considerable number of patients with genetically proven types of the disease have unusual phenotypic presentation. The aim of our study was to evaluate motor unit reorganization reflected by various electrophysiological abnormalities in myotonic dystrophies and to compare findings between type 1 (DM 1) and type 2 myotonic dystrophy (DM2). Quantitative electromyography (EMG) recordings in 63 patients (33 with DM1 and 30 with DM2) from the biceps brachii (BB), rectus femoris (RF), first dorsal interosseus (FDI), and tibialis anterior (TA) muscles were analyzed. Mean amplitude and size index (SI) of motor unit potentials recorded in TA and RF muscles, mean potential duration in TA, and mean SI and the number of outliers with amplitude above the normal range in BB were significantly increased in DM2 as compared to DM1. Myotonic discharges were recorded more frequently in DM1 than in DM2. EMG findings significantly differ between DM1 and DM2. The presence of high amplitude potentials in lower limb muscles in DM2 patients, atypical for myogenic muscle lesions, could be explained by muscle fiber hypertrophy observed in muscle biopsies.

  7. Participation restriction in childhood phenotype of myotonic dystrophy type 1: a systematic retrospective chart review.

    PubMed

    Gagnon, Cynthia; Kierkegaard, Marie; Blackburn, Catherine; Chrestian, Nicolas; Lavoie, Mélissa; Bouchard, Marie-Frédéric; Mathieu, Jean

    2017-03-01

    Myotonic dystrophy type 1 (DM1), a neuromuscular disorder, is divided into four clinical phenotypes: congenital; childhood; adult-onset, and late-onset. Publications about the childhood phenotype, especially the long-term outcome, are scarce. The aims of this study were to assess and describe participation outcomes in adults with the childhood phenotype. A retrospective chart methodology. Data were extracted from health records for 63 adults with childhood DM1 (32 males, 31 females; mean age 34y, standard deviation [SD] 11y 6mo; range 18-54y) who had attended the Saguenay Neuromuscular Clinic, Canada. Thirty-four adults (54%) lived with their parents or in foster homes, and most patients needed services or help to live independently. A significant proportion (22%) were isolated in regard to friendship. Very few adults had children, although 33% lived with a spouse. The majority of patients (86%) relied on social security and only one person was currently working. Financial responsibilities were often an issue and 13 (21%) were under legal guardianship. This study showed that patients with the childhood phenotype present a guarded prognosis regarding long-term social participation. These participation restrictions could be related to behavioural, cognitive, and social stigma problems in childhood. This study illustrates the absolute necessity to pursue an interdisciplinary follow-up of these patients when they are reaching adulthood. © 2016 Mac Keith Press.

  8. The myotonic dystrophy kinase 3{prime}-untranslated region and its effect on gene expression

    SciTech Connect

    Ang, C.W.Y.; Sabourin, L.A.; Narang, M.A.

    1994-09-01

    Myotonic dystrophy (DM) is an autosomal dominant neuromuscular disease involving the expansion of an unstable CTG repeat in the 3{prime}-untranslated (3{prime}-UTR) region of the DM kinase (DMK) gene. Increased levels of mRNA in congenital compared to normal tissue have been shown, suggesting elevated DMK levels may be responsible for the disease phenotype. To study the effect of the DMK 3{prime}UTR on gene expression, a reporter gene system was constructed using the constitutive CMV promoter with the chloramphenicol acetyl transferase (CAT) open reading frame and the DMK 3{prime}UTR containing from 5 repeats up to 90 repeats. Transient transfection into a rhabdomyosarcoma cell line shows a three-fold increase in CAT activity from constructs containing a wildtype 3{prime}UTR (5 and 20 repeats) compared to a control construct containing only a poly(A) signal. Reporter constructs with repeats in the protomutation (50 repeats) and mutation (90 repeats) range show a greater than 10-fold increase over control CAT activity. These results suggest the presence of elements in the DMK 3{prime}UTR capable of conferring increased gene expression. We are currently investigating cell-specific activity of the constructs and conducting deletion mapping to identify regulatory elements in the 3{prime}-UTR.

  9. Anatomy of a founder effect: myotonic dystrophy in Northeastern Quebec.

    PubMed

    Yotova, Vania; Labuda, Damian; Zietkiewicz, Ewa; Gehl, Dominik; Lovell, Alan; Lefebvre, Jean-François; Bourgeois, Stéphane; Lemieux-Blanchard, Emilie; Labuda, Marcin; Vézina, Hélène; Houde, Louis; Tremblay, Marc; Toupance, Bruno; Heyer, Evelyne; Hudson, Thomas J; Laberge, Claude

    2005-07-01

    Founder effects are largely responsible for changes in frequency profiles of genetic variants in local populations or isolates. They are often recognized by elevated incidence of certain hereditary disorders as observed in regions of Charlevoix and Saguenay-Lac-Saint-Jean (SLSJ) in Northeastern Quebec. Dominantly transmitted myotonic dystrophy (DM1) is highly prevalent in SLSJ where its carrier rate reaches 1/550, compared with 1/5,000 to 1/50,000 elsewhere. To shed light on the origin of DM1 in this region, we have screened 50 nuclear DM1 families from SLSJ and studied the genetic variation in a 2.05 Mb (2.9 cM) segment spanning the site of the expansion mutation. The markers analyzed included 22 biallelic SNPs and two microsatellites. Among 50 independent DM1 chromosomes, we distinguished ten DM1-associated haplotypes and grouped them into three haplotype families, A, B and C, based on the relevant extent of allele sharing between them. To test whether the data were consistent with a single entry of the mutation into SLSJ, we evaluated the age of the founder effect from the proportion of recombinant haplotypes. Taking the prevalent haplotype A1_21 (58%) as ancestral to all the disease-associated haplotypes in this study, the estimated age of the founder effect was 19 generations, long predating the colonization of Nouvelle-France. In contrast, considering A1_21 as ancestral to the haplotype family A only, yielded the estimated founder age of nine generations, consistent with the settlement of Charlevoix at the turn of 17th century and subsequent colonization of SLSJ. We conclude that it was the carrier of haplotype A (present day carrier rate of 1/730) that was a "driver" of the founder effect, while minor haplotypes B and C, with corresponding carrier rates of 1/3,000 and 1/10,000, respectively, contribute DM1 to the incidence level known in other populations. Other studies confirm that this might be a general scenario in which a major "driver" mutation

  10. Medication adherence in patients with myotonic dystrophy and facioscapulohumeral muscular dystrophy.

    PubMed

    Fitzgerald, Bryan P; Conn, Kelly M; Smith, Joanne; Walker, Andrew; Parkhill, Amy L; Hilbert, James E; Luebbe, Elizabeth A; Moxley, Richard T

    2016-12-01

    Myotonic dystrophy (DM) and facioscapulohumeral muscular dystrophy (FSHD) are the two most common adult muscular dystrophies and have progressive and often disabling manifestations. Higher levels of medication adherence lead to better health outcomes, especially important to patients with DM and FSHD because of their multisystem manifestations and complexity of care. However, medication adherence has not previously been studied in a large cohort of DM type 1 (DM1), DM type 2 (DM2), and FSHD patients. The purpose of our study was to survey medication adherence and disease manifestations in patients enrolled in the NIH-supported National DM and FSHD Registry. The study was completed by 110 DM1, 49 DM2, and 193 FSHD patients. Notable comorbidities were hypertension in FSHD (44 %) and DM2 (37 %), gastroesophageal reflux disease in DM1 (24 %) and DM2 (31 %) and arrhythmias (29 %) and thyroid disease (20 %) in DM1. Each group reported high levels of adherence based on regimen complexity, medication costs, health literacy, side effect profile, and their beliefs about treatment. Only dysphagia in DM1 was reported to significantly impact medication adherence. Approximately 35 % of study patients reported polypharmacy (taking 6 or more medications). Of the patients with polypharmacy, the DM1 cohort was significantly younger (mean 55.0 years) compared to DM2 (59.0 years) and FSHD (63.2 years), and had shorter disease duration (mean 26 years) compared to FSHD (26.8 years) and DM2 (34.8 years). Future research is needed to assess techniques to ease pill swallowing in DM1 and to monitor polypharmacy and potential drug interactions in DM and FSHD.

  11. Anticipation in myotonic dystrophy type 1 parents with small CTG expansions.

    PubMed

    Pratte, Annabelle; Prévost, Claude; Puymirat, Jack; Mathieu, Jean

    2015-04-01

    Myotonic dystrophy type 1 is the most common form of adult muscular dystrophy and has the world's highest prevalence in the Saguenay-Lac-St-Jean region, due to a founder effect. This autosomal dominant disorder results from an unstable CTG repeat expansion in DMPK. This region of Canada has had a family screening and predictive testing program for this disorder since 1988. Heterozygotes for small expansions (50-100 CTG repeats) can be asymptomatic or minimally affected. The aim of this study was to assess anticipation for these individuals. At the time of this study, the molecular data of 40 individuals and their 76 affected children were available. We compared 76 parent-child pairs. Most offspring (92.1%) had a larger number of repeats than their parent and the median number of repeats in the offspring was 325 (range, 57-2000). The number of CTG repeats was significantly greater when the mutation was transmitted by a father (median, 425 repeats; range, 70-2000), than when it was transmitted by a mother (median, 200 repeats; range, 57-1400). The majority (65.8%) of children also had a more severe phenotype than their parent but the sex of the parent had no significant influence on the severity of the child's phenotype. No congenital phenotype was observed. These results confirm that anticipation is present even when the parent is heterozygous for a small CTG expansion. The parental sex has an impact on the size of the repeat in the next generation, larger increases being transmitted by males with a small expansion. © 2015 Wiley Periodicals, Inc.

  12. Longitudinal in vivo muscle function analysis of the DMSXL mouse model of myotonic dystrophy type 1.

    PubMed

    Decostre, Valérie; Vignaud, Alban; Matot, Béatrice; Huguet, Aline; Ledoux, Isabelle; Bertil, Emilie; Gjata, Bernard; Carlier, Pierre G; Gourdon, Geneviève; Hogrel, Jean-Yves

    2013-12-01

    Myotonic dystrophy is the most common adult muscle dystrophy. In view of emerging therapies, which use animal models as a proof of principle, the development of reliable outcome measures for in vivo longitudinal study of mouse skeletal muscle function is becoming crucial. To satisfy this need, we have developed a device to measure ankle dorsi- and plantarflexion torque in rodents. We present an in vivo 8-month longitudinal study of the contractile properties of the skeletal muscles of the DMSXL mouse model of myotonic dystrophy type 1. Between 4 and 12 months of age, we observed a reduction in muscle strength in the ankle dorsi- and plantarflexors of DMSXL compared to control mice although the strength per muscle cross-section was normal. Mild steady myotonia but no abnormal muscle fatigue was also observed in the DMSXL mice. Magnetic resonance imaging and histological analysis performed at the end of the study showed respectively reduced muscle cross-section area and smaller muscle fibre diameter in DMSXL mice. In conclusion, our study demonstrates the feasibility of carrying out longitudinal in vivo studies of muscle function over several months in a mouse model of myotonic dystrophy confirming the feasibility of this method to test preclinical therapeutics.

  13. Myotonic dystrophy: Size- and sex-dependent dynamics of CTG meiotic instability, and somatic mosaicism

    SciTech Connect

    Lavedan, C.; Rabes, J.P.; Duros, C.; Savoy, D. ); Hofmann-Radvanyi, H.; Dehaupas, I.; Luce, S.; Junien, C. Hopital A. Pare, Boulogne ); Shelbourne, P.; Johnson, K. )

    1993-05-01

    Myotonic dystrophy (DM) is a progressive neuromuscular disorder which results from elongations of an unstable (CTG)n repeat, located in the 3' untranslated region of the DM gene. A correlation has been demonstrated between the increase in the repeat number of this sequence and the severity of the disease. However, the clinical status of patients cannot be unambiguously ascertained solely on the basis of the number of CTG repeats. Moreover, the exclusive maternal inheritance of the congenital form remains unexplained. The authors observation of differently sized repeats in various DM tissues from the same individual may explain why the size of the mutation observed in lymphocytes does not necessarily correlate with the severity and nature of symptoms. Through a molecular and genetic study of 142 families including 418 DM patients, the authors have investigated the dynamics of the CTG repeat meiotic instability. A positive correlation between the size of the repeat and the intergenerational enlargement was observed similarly through male and female meioses for l[le]0.5-kb CTG sequences. Beyond 0.5 kb, the intergenerational variation was more important through female meioses, whereas a tendency to compression was observed almost exclusively in male meioses, for [ge] 1.5-kb fragments. This implies a size- and sex-dependent meiotic instability. Moreover, segregation analysis supports the hypothesis of a maternal as well as a familial predisposition for the occurrence of the congenital form. Finally, this analysis reveals a significant excess of transmitting grandfathers partially accounted for by increased fertility in affected males. 23 refs., 7 figs.

  14. [Congenital muscular dystrophies in children].

    PubMed

    Scavone-Mauro, Cristina; Barros, Graciela

    2013-09-06

    From the clinical and genetic point of view, congenital muscular dystrophies (CMD) are a heterogenic group of diseases within neuromuscular pathologies. The best known forms are: merosin deficiency CMD, collagen VI deficiency CMD, LMNA-related CMD, selenoprotein-related CMD (SEPN1) and alpha-dystroglycan-related CMD. They present with a broad spectrum of clinical phenotypes. Most of them are transmitted by recessive autosomal inheritance. The initial manifestations very often begin in infancy or in the neonatal period. There are clinical suspicions of the existence of hypotonia and paresis, and they are characterised by a dystrophic pattern in the muscular biopsy (muscle replaced by fibroadipose tissue, with necrosis and cell regeneration). Advances in the understanding of the molecular pathogenesis of CMD have made it possible to make further progress in the classification of the different subtypes. The aim of this review is to comment on the advances made in recent years as regards the classification of CMD in terms of genetics, the proteins involved and their clinical presentation.

  15. Fuchs' Endothelial Corneal Dystrophy and RNA Foci in Patients With Myotonic Dystrophy.

    PubMed

    Mootha, V Vinod; Hansen, Brock; Rong, Ziye; Mammen, Pradeep P; Zhou, Zhengyang; Xing, Chao; Gong, Xin

    2017-09-01

    The most common cause of Fuchs' endothelial corneal dystrophy (FECD) is an intronic CTG repeat expansion in TCF4. Expanded CUG repeat RNA colocalize with splicing factor, muscleblind-like 1 (MBNL1), in nuclear foci in endothelium as a molecular hallmark. Myotonic dystrophy type 1 (DM1) is a neuromuscular disorder caused by a CTG repeat expansion in the 3'-untranslated region (UTR) of DMPK. In this study, we examine for RNA-MBNL1 foci in endothelial cells of FECD subjects with DM1, test the hypothesis that DM1 patients are at risk for FECD, and determine prevalence of TCF4 and DMPK expansions in a FECD cohort. Using FISH, we examined for nuclear RNA-MBNL1 foci in endothelial cells from FECD subjects with DM1. We examined 13 consecutive unrelated DM1 patients for FECD using slit-lamp and specular microscopy. We genotyped TCF4 and DMPK repeat polymorphisms in a FECD cohort of 317 probands using short-tandem repeat and triplet repeat-primed PCR assays. We detected abundant nuclear RNA foci colocalizing with MBNL1 in endothelial cells of FECD subjects with DM1. Six of thirteen DM1 patients (46%) had slit-lamp and specular microscopic findings of FECD, compared to 4% disease prevalence (P = 5.5 × 10-6). As expected, 222 out of 317 (70%) FECD probands harbored TCF4 expansion, while one subject harbored DMPK expansion without prior diagnosis of DM1. Our work suggests that DM1 patients are at risk for FECD. DMPK mutations contribute to the genetic burden of FECD but are uncommon. We establish a connection between two repeat expansion disorders converging upon RNA-MBNL1 foci and FECD.

  16. The Myotonic Dystrophy Health Index: Correlations with Clinical Tests and Patient Function

    PubMed Central

    Heatwole, Chad; Bode, Rita; Johnson, Nicholas; Dekdebrun, Jeanne; Dilek, Nuran; Eichinger, Katy; Hilbert, James E.; Logigian, Eric; Luebbe, Elizabeth; Martens, William; McDermott, Michael P.; Pandya, Shree; Puwanant, Araya; Rothrock, Nan; Thornton, Charles; Vickrey, Barbara G.; Victorson, David; Moxley, Richard T.

    2015-01-01

    Introduction The Myotonic Dystrophy Health Index (MDHI) is a disease-specific patient-reported outcome measure. Here we examine the associations between the MDHI and other measures of disease burden in a cohort of individuals with myotonic dystrophy type-1 (DM1). Methods We conducted a cross-sectional study of 70 patients with DM1. We examined the associations between MDHI total and subscale scores and scores from other clinical tests. Participants completed assessments of strength, myotonia, motor and respiratory function, ambulation, and body composition. Participants also provided blood samples, underwent physician evaluations, and completed other patient-reported outcome measures. Results MDHI total and subscale scores were strongly associated with muscle strength, myotonia, motor function, and other clinical measures. Conclusion Patient-reported health status, as measured by the MDHI, is associated with alternative measures of clinical health. These results support the use of the MDHI as a valid tool to measure disease burden in DM1 patients. PMID:26044513

  17. Rac-1 and Raf-1 kinases, components of distinct signaling pathways, activate myotonic dystrophy protein kinase

    NASA Technical Reports Server (NTRS)

    Shimizu, M.; Wang, W.; Walch, E. T.; Dunne, P. W.; Epstein, H. F.

    2000-01-01

    Myotonic dystrophy protein kinase (DMPK) is a serine-threonine protein kinase encoded by the myotonic dystrophy (DM) locus on human chromosome 19q13.3. It is a close relative of other kinases that interact with members of the Rho family of small GTPases. We show here that the actin cytoskeleton-linked GTPase Rac-1 binds to DMPK, and coexpression of Rac-1 and DMPK activates its transphosphorylation activity in a GTP-sensitive manner. DMPK can also bind Raf-1 kinase, the Ras-activated molecule of the MAP kinase pathway. Purified Raf-1 kinase phosphorylates and activates DMPK. The interaction of DMPK with these distinct signals suggests that it may play a role as a nexus for cross-talk between their respective pathways and may partially explain the remarkable pleiotropy of DM.

  18. Correlation between decreased myocardial glucose phosphorylation and the DNA mutation size in myotonic dystrophy.

    PubMed

    Annane, D; Duboc, D; Mazoyer, B; Merlet, P; Fiorelli, M; Eymard, B; Radvanyi, H; Junien, C; Fardeau, M; Gajdos, P

    1994-12-01

    Myotonic dystrophy, the most common form of adult dystrophy, has been shown to be caused by amplification of CTG triplet repeat in the 3' untranslated region of a protein kinase gene located on chromosome 19. Impaired glucose metabolism has been suggested as a possible explanation of brain and skeletal muscle involvement in this multisystem disease. We investigated whether myocardial glucose metabolism is impaired in myotonic dystrophy and whether this impairment is related to the size of the mutation. The myocardial metabolic rate for glucose (MMRGlu, mumol.min-1.g-1), K1 (blood-to-tissue transfer constant), k2 (tissue-to-blood transfer constant), and k3 (phosphorylation rate constant) were determined in 7 control subjects and 12 patients with myotonic dystrophy by using parametric images generated from dynamic cardiac positron emission tomography (PET) and 18F-fluoro-2-deoxy-glucose studies. The expansion of the CTG triplet repeats was analyzed in patients with the probe cDNA25 after EcoRI digestion. Nonparametric tests were used to compare quantitative variables between control subjects and patients. The correlations between the size of the mutation and PET parameters were studied by linear regression. MMRGlu and k3 were significantly decreased in patients compared with control subjects (0.39 +/- 0.20 versus 0.64 +/- 0.25, P = .03, and 0.09 +/- 0.07 versus 0.24 +/- 0.21, P = .03, respectively), whereas K1 and k2 were not statistically different between control subjects and patients. MMRGlu and k3 correlate inversely with the length of the CTG triplet repeat (r = -.65 and P = .03 for MMRGlu, and r = -.85 and P = .001 for k3, respectively). In myotonic dystrophy, the observed reductions in MMRGlu and phosphorylation are inversely linked to the length of the mutation. This observation suggests that impaired modulation of a protein kinase involved in myocardial hexokinase activation may give a pathophysiological schema to relate the molecular defect and the abnormal

  19. The Myotonic Dystrophy Health Index: Italian validation of a disease-specific outcome measure.

    PubMed

    Sansone, Valeria A; Lizio, Andrea; Greco, Lucia; Gragnano, Gaia; Zanolini, Alice; Gualandris, Marco; Iatomasi, Marino; Heatwole, Chad

    2017-07-10

    The Myotonic Dystrophy Health Index (MDHI) is a disease-specific, self-reported outcome measure that assesses total disease burden and 17 areas of Myotonic Dystrophy type 1 (DM1) specific health. This study translated the MDHI into Italian and validated the instrument using a cohort of Italian DM1 patients. Italian DM1 patients were interviewed regarding the form and content of the instrument. Thirty-eight DM1 patients were subsequently recruited to test the reliability and concurrent validity of the instrument by serially completing the MDHI and a battery of clinical tests. Lastly, we determined the internal consistency of the Italian MDHI and each of its subscales. The internal consistency was excellent in the total Italian MDHI score and acceptable in all of its subscales; the test-retest reliability was high (intraclass correlation coefficient = 0.95); Italian MDHI total scores and subscales were associated with neuromuscular function, cognitive and social health, respiratory function, and quality of life. Overall, the Italian MDHI is valid and well suited to measure the multi-dimensional aspects of disease burden in Myotonic Dystrophy clinical trials. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Prevalence of congenital muscular dystrophy in Italy

    PubMed Central

    Graziano, Alessandra; Bianco, Flaviana; D'Amico, Adele; Moroni, Isabella; Messina, Sonia; Bruno, Claudio; Pegoraro, Elena; Mora, Marina; Astrea, Guja; Magri, Francesca; Comi, Giacomo P.; Berardinelli, Angela; Moggio, Maurizio; Morandi, Lucia; Pini, Antonella; Petillo, Roberta; Tasca, Giorgio; Monforte, Mauro; Minetti, Carlo; Mongini, Tiziana; Ricci, Enzo; Gorni, Ksenija; Battini, Roberta; Villanova, Marcello; Politano, Luisa; Gualandi, Francesca; Ferlini, Alessandra; Muntoni, Francesco; Santorelli, Filippo Maria; Bertini, Enrico; Pane, Marika

    2015-01-01

    Objective: We provide a nationwide population study of patients with congenital muscular dystrophy in Italy. Methods: Cases were ascertained from the databases in all the tertiary referral centers for pediatric neuromuscular disorders and from all the genetic diagnostic centers in which diagnostic tests for these forms are performed. Results: The study includes 336 patients with a point prevalence of 0.563 per 100,000. Mutations were identified in 220 of the 336 (65.5%). The cohort was subdivided into diagnostic categories based on the most recent classifications on congenital muscular dystrophies. The most common forms were those with α-dystroglycan glycosylation deficiency (40.18%) followed by those with laminin α2 deficiency (24.11%) and collagen VI deficiency (20.24%). The forms of congenital muscular dystrophy related to mutations in SEPN1 and LMNA were less frequent (6.25% and 5.95%, respectively). Conclusions: Our study provides for the first time comprehensive epidemiologic information and point prevalence figures for each of the major diagnostic categories on a large cohort of congenital muscular dystrophies. The study also reflects the diagnostic progress in this field with an accurate classification of the cases according to the most recent gene discoveries. PMID:25653289

  1. Temperament and character in patients with classical myotonic dystrophy type 1 (DM-1).

    PubMed

    Winblad, S; Lindberg, C; Hansen, S

    2005-04-01

    This study was designed to investigate personality in classical Myotonic Dystrophy (DM-1). Forty-six patients with DM-1 (25 women and 21 men), 31 healthy controls and 37 subjects in a contrast group, consisting of patients with other muscle disorders (spinal muscular atrophy, facioscapulohumeral dystrophy and limb girdle muscular dystrophy), completed the Temperament and Character Inventory (TCI) (Cloninger, 1994). We aimed to establish whether CTG triplet repeat size correlated with ratings of personality dimensions in the TCI. The DM-1 patients scored significantly higher on the TCI dimension Harm avoidance and lower on Persistence, Self-directedness and Cooperativeness. Signs of a personality disorder were found in 20% of the DM-1 patients. No correlation was found between the number of CTG repeats and scores in the TCI. This study indicates deviant personality in classical DM-1 regarding temperament and character, both in comparison to healthy controls and to patients with other muscle disorders with no known brain disorder.

  2. Orthopaedic Disorders in Myotonic Dystrophy Type 1: descriptive clinical study of 21 patients.

    PubMed

    Schilling, Lisa; Forst, Raimund; Forst, Jürgen; Fujak, Albert

    2013-12-01

    Myotonic Dystrophy Type 1 (DM1) is the most common form of hereditary myopathy presenting in adults. This autosomal-dominant systemic disorder is caused by a CTG repeat, demonstrating various symptoms. A mild, classic and congenital form can be distinguished. Often the quality of life is reduced by orthopaedic problems, such as muscle weakness, contractures, foot or spinal deformities, which limit patients' mobility.The aim of our study was to gather information about the orthopaedic impairments in patients with DM1 in order to improve the medical care of patients, affected by this rare disease. A retrospective clinical study was carried out including 21 patients (11 male and 10 female), all diagnosed with DM1 by genetic testing. All patients were seen during our special consultations for neuromuscular diseases, during which patients were interviewed and examined. We also reviewed surgery reports of our hospitalized patients. We observed several orthopaedic impairments: spinal deformities (scoliosis, hyperkyphosis, rigid spine), contractures (of the upper extremities and the lower extremities), foot deformities (equinus deformity, club foot, pes cavus, pes planovalgus, pes cavovarus, claw toes) and fractures.Five patients were affected by pulmonary diseases (obstructive airway diseases, restrictive lung dysfunctions). Twelve patients were affected by cardiac disorders (congenital heart defects, valvular heart defects, conduction disturbances, pulmonary hypertension, cardiomyopathy).Our patients received conservative therapy (physiotherapy, logopaedic therapy, ergotherapy) and we prescribed orthopaedic technical devices (orthopaedic custom-made shoes, insoles, lower and upper leg orthoses, wheelchair, Rehab Buggy). We performed surgery for spinal and foot deformities: the scoliosis of one patient was stabilized and seven patients underwent surgery for correction of foot deformities. An orthopaedic involvement in DM1 patients should not be underestimated. The most

  3. Orthopaedic Disorders in Myotonic Dystrophy Type 1: descriptive clinical study of 21 patients

    PubMed Central

    2013-01-01

    Background Myotonic Dystrophy Type 1 (DM1) is the most common form of hereditary myopathy presenting in adults. This autosomal-dominant systemic disorder is caused by a CTG repeat, demonstrating various symptoms. A mild, classic and congenital form can be distinguished. Often the quality of life is reduced by orthopaedic problems, such as muscle weakness, contractures, foot or spinal deformities, which limit patients’ mobility. The aim of our study was to gather information about the orthopaedic impairments in patients with DM1 in order to improve the medical care of patients, affected by this rare disease. Methods A retrospective clinical study was carried out including 21 patients (11 male and 10 female), all diagnosed with DM1 by genetic testing. All patients were seen during our special consultations for neuromuscular diseases, during which patients were interviewed and examined. We also reviewed surgery reports of our hospitalized patients. Results We observed several orthopaedic impairments: spinal deformities (scoliosis, hyperkyphosis, rigid spine), contractures (of the upper extremities and the lower extremities), foot deformities (equinus deformity, club foot, pes cavus, pes planovalgus, pes cavovarus, claw toes) and fractures. Five patients were affected by pulmonary diseases (obstructive airway diseases, restrictive lung dysfunctions). Twelve patients were affected by cardiac disorders (congenital heart defects, valvular heart defects, conduction disturbances, pulmonary hypertension, cardiomyopathy). Our patients received conservative therapy (physiotherapy, logopaedic therapy, ergotherapy) and we prescribed orthopaedic technical devices (orthopaedic custom-made shoes, insoles, lower and upper leg orthoses, wheelchair, Rehab Buggy). We performed surgery for spinal and foot deformities: the scoliosis of one patient was stabilized and seven patients underwent surgery for correction of foot deformities. Conclusions An orthopaedic involvement in DM1

  4. Can long-term thiamine treatment improve the clinical outcomes of myotonic dystrophy type 1?

    PubMed Central

    Costantini, Antonio; Trevi, Erika; Pala, Maria Immacolata; Fancellu, Roberto

    2016-01-01

    Myotonic dystrophy type 1, also known as Steinert's disease, is an autosomal dominant disorder with multisystemic clinical features affecting the skeletal and cardiac muscles, the eyes, and the endocrine system. Thiamine (vitamin B1) is a cofactor of fundamental enzymes involved in the energetic cell metabolism; recent studies described its role in oxidative stress, protein processing, peroxisomal function, and gene expression. Thiamine deficiency is critical mainly in the central and peripheral nervous system, as well as in the muscular cells. Our aim was to investigate the potential therapeutical effects of long-term treatment with thiamine in myotonic dystrophy type 1 in an observational open-label pilot study. We described two patients with myotonic dystrophy type 1 treated with intramuscular thiamine 100 mg twice a week for 12 or 11 months. We evaluated the patients using the grading of muscle strength according to Medical Research Council (MRC), the Muscular Impairment Rating Scale (MIRS), and the Modified Barthel index. High-dose thiamine treatment was well tolerated and effective in improving the motor symptomatology, particularly the muscle strength evaluated with the MRC scale, and the patients’ activities of daily living using the Modified Barthel Index. At the end of treatment, the MRC score was 5 in the proximal muscles and 2–4 in the distal muscles (the MRC score before the treatment was 3–4 and 1–3, respectively). The MIRS grade improved by 25% compared to baseline for both patients. In patient #1, the Modified Barthel Index improved by 44%, and in patient #2 by 29%. These findings suggest that clinical outcomes are improved by long-term thiamine treatment. PMID:27857755

  5. [Educational and Professional Qualifications of Adults With Myotonic Dystrophies - A Misleading Perception by the Myopathic Face?].

    PubMed

    Stahl, K; Wenninger, S; Schüller, A; Montagnese, F; Schoser, B

    2016-04-01

    Myotonic dystrophies types 1 and 2 (DM1 / DM2) are the most frequent inherited progressive, segmental progeroid, multisystemic neuromuscular diseases in adulthood. The executive impairment is one of the key disease features. The myopathic face triggers the general perception of DM1 patients being associated with a low educational level. We used a standardized questionnaire to evaluate educational levels in adults with genetically confirmed DM1 and DM2 in comparison to data of the general population. Investigated topics included the level of education, e. g. the highest university degree aquired. Out of a total cohort of 546 DM patients, 125 DM1 and 156 DM2 patients (51 %) participated in this study. There was no statistically significant difference between the two collectives as far as high school levels are concerned. 50.4 % of DM1 and 48.3 % of DM2 patients obtained the higher education entrance qualification compared to 29.6 % of the normal German population. However, there were significant differences between the two collectives in "spelling problems" (DM1 cohort: p = 0.039), "difficulty in mental arithmetic" (p = 0.043), and classification of patients "with learning difficulties" (p = 0.012). Misled by a myopathic face, many physicians associate myotonic dystrophy with cognitive deficiency. Based on our study, the minimal deviation between DM1 and DM2 and the normal German population indicates that the multisystemic disease does not significantly influence the maximum attainable level of education in adults with DM1. In summary, physicians should be aware that the general educational levels are rather normal in patients with myotonic dystrophy type 1 and rethink their perception of DM1 patients. © Georg Thieme Verlag KG Stuttgart · New York.

  6. A journey in bioinspired supramolecular chemistry: from molecular tweezers to small molecules that target myotonic dystrophy

    PubMed Central

    2016-01-01

    Summary This review summarizes part of the author’s research in the area of supramolecular chemistry, beginning with his early life influences and early career efforts in molecular recognition, especially molecular tweezers. Although designed to complex DNA, these hosts proved more applicable to the field of host–guest chemistry. This early experience and interest in intercalation ultimately led to the current efforts to develop small molecule therapeutic agents for myotonic dystrophy using a rational design approach that heavily relies on principles of supramolecular chemistry. How this work was influenced by that of others in the field and the evolution of each area of research is highlighted with selected examples. PMID:26877815

  7. Preferential Nucleosome Assembly at DNA Triplet Repeats from the Myotonic Dystrophy Gene

    NASA Astrophysics Data System (ADS)

    Wang, Yuh-Hwa; Amirhaeri, Sorour; Kang, Seongman; Wells, Robert D.; Griffith, Jack D.

    1994-07-01

    The expansion of CTG repeats in DNA occurs in or near genes involved in several human diseases, including myotonic dystrophy and Huntington's disease. Nucleosomes, the basic structural element of chromosomes, consist of 146 base pairs of DNA coiled about an octamer of histone proteins and mediate general transcriptional repression. Electron microscopy was used to examine in vitro the nucleosome assembly of DNA containing repeating CTG triplets. The efficiency of nucleosome formation increased with expanded triplet blocks, suggesting that such blocks may repress transcription through the creation of stable nucleosomes.

  8. Anesthetic Considerations in a Patient with Myotonic Dystrophy for Hip Labral Repair

    PubMed Central

    Wang, David; Ludwin, Danielle

    2017-01-01

    Myotonic Dystrophy (DM) affects multiple organ systems. Disorders such as hyperthyroidism, progressive musculoskeletal weakness, cardiac dysrhythmias, hypoventilation, and cognitive-behavioral disorders may be present in these patients. Thorough preoperative assessment and anesthetic planning are required to minimize the risk of anesthetic complications. Patients with DM can exhibit exquisite sensitivity to sedatives, neuromuscular blocking agents, and volatile anesthetics, resulting in potential postoperative complications. There is limited literature available on successful anesthetic techniques for the DM patient. We present this case report to add to our current fund of knowledge. PMID:28316843

  9. Anesthetic Considerations in a Patient with Myotonic Dystrophy for Hip Labral Repair.

    PubMed

    Go, Ramon; Wang, David; Ludwin, Danielle

    2017-01-01

    Myotonic Dystrophy (DM) affects multiple organ systems. Disorders such as hyperthyroidism, progressive musculoskeletal weakness, cardiac dysrhythmias, hypoventilation, and cognitive-behavioral disorders may be present in these patients. Thorough preoperative assessment and anesthetic planning are required to minimize the risk of anesthetic complications. Patients with DM can exhibit exquisite sensitivity to sedatives, neuromuscular blocking agents, and volatile anesthetics, resulting in potential postoperative complications. There is limited literature available on successful anesthetic techniques for the DM patient. We present this case report to add to our current fund of knowledge.

  10. Rare Muscular Dystrophies: Congenital, Distal, Emery-Dreifuss and Oculopharyngeal Muscular Dystrophies

    MedlinePlus

    ... 14 CMD, DD, EDMD and OPMD • ©2011 MDA Classification of Congenital Muscular Dystrophies Type of CMD Merosin- ... Chromosome 1 gene, recessive See illustration, page 5. Classification of Distal Muscular Dystrophies Type of CMD Welander’s ...

  11. Aberrant alternative splicing and extracellular matrix gene expression in mouse models of myotonic dystrophy

    PubMed Central

    Du, Hongqing; Cline, Melissa S.; Osborne, Robert J.; Tuttle, Daniel L.; Clark, Tyson A.; Donohue, John Paul; Hall, Megan P.; Shiue, Lily; Swanson, Maurice S.; Thornton, Charles A.; Ares, Manuel

    2009-01-01

    Myotonic dystrophy (DM1) is associated with expression of expanded CTG DNA repeats as RNA (CUGexp RNA). To test whether CUGexp RNA creates a global splicing defect, we compared skeletal muscle of two mouse DM1 models, one expressing a CTGexp transgene, and another homozygous for a defective Mbnl1 gene. Strong correlation in splicing changes for ~100 new Mbnl1-regulated exons indicates loss of Mbnl1 explains >80% of the splicing pathology due to CUGexp RNA. In contrast, only about half of mRNA level changes can be attributed to loss of Mbnl1, indicating CUGexp RNA has Mbnl1-independent effects, particularly on mRNAs for extracellular matrix (ECM) proteins. We propose that CUGexp RNA causes two separate effects: loss of Mbnl1 function, disrupting splicing, and loss of another function that disrupts ECM mRNA regulation, possibly mediated by MBNL2. These findings reveal unanticipated similarities between DM1 and other muscular dystrophies. PMID:20098426

  12. Manumycin A corrects aberrant splicing of Clcn1 in myotonic dystrophy type 1 (DM1) mice.

    PubMed

    Oana, Kosuke; Oma, Yoko; Suo, Satoshi; Takahashi, Masanori P; Nishino, Ichizo; Takeda, Shin'ichi; Ishiura, Shoichi

    2013-01-01

    Myotonic dystrophy type 1 (DM1) is the most common muscular dystrophy in adults and as yet no cure for DM1. Here, we report the potential of manumycin A for a novel DM1 therapeutic reagent. DM1 is caused by expansion of CTG repeat. Mutant transcripts containing expanded CUG repeats lead to aberrant regulation of alternative splicing. Myotonia (delayed muscle relaxation) is the most commonly observed symptom in DM1 patients and is caused by aberrant splicing of the skeletal muscle chloride channel (CLCN1) gene. Identification of small-molecule compounds that correct aberrant splicing in DM1 is attracting much attention as a way of improving understanding of the mechanism of DM1 pathology and improving treatment of DM1 patients. In this study, we generated a reporter screening system and searched for small-molecule compounds. We found that manumycin A corrects aberrant splicing of Clcn1 in cell and mouse models of DM1.

  13. Diagnostic approach to the congenital muscular dystrophies

    PubMed Central

    Bönnemann, Carsten G.; Wang, Ching H.; Quijano-Roy, Susana; Deconinck, Nicolas; Bertini, Enrico; Ferreiro, Ana; Muntoni, Francesco; Sewry, Caroline; Béroud, Christophe; Mathews, Katherine D.; Moore, Steven A.; Bellini, Jonathan; Rutkowski, Anne; North, Kathryn N.

    2017-01-01

    Congenital muscular dystrophies (CMDs) are early onset disorders of muscle with histological features suggesting a dystrophic process. The congenital muscular dystrophies as a group encompass great clinical and genetic heterogeneity so that achieving an accurate genetic diagnosis has become increasingly challenging, even in the age of next generation sequencing. In this document we review the diagnostic features, differential diagnostic considerations and available diagnostic tools for the various CMD subtypes and provide a systematic guide to the use of these resources for achieving an accurate molecular diagnosis. An International Committee on the Standard of Care for Congenital Muscular Dystrophies composed of experts on various aspects relevant to the CMDs performed a review of the available literature as well as of the unpublished expertise represented by the members of the committee and their contacts. This process was refined by two rounds of online surveys and followed by a three-day meeting at which the conclusions were presented and further refined. The combined consensus summarized in this document allows the physician to recognize the presence of a CMD in a child with weakness based on history, clinical examination, muscle biopsy results, and imaging. It will be helpful in suspecting a specific CMD subtype in order to prioritize testing to arrive at a final genetic diagnosis. PMID:24581957

  14. Comparison of mechanomyography and acceleromyography for the assessment of rocuronium induced neuromuscular block in myotonic dystrophy type 1.

    PubMed

    Vanlinthout, L E H; Booij, L H D J; van Egmond, J; Robertson, E N

    2010-06-01

    We measured acceleromyography and mechanomyography simultaneously with monitoring of rocuronium-induced neuromuscular block in four patients with myotonic dystrophy type 1. Furthermore, we compared neuromuscular block measures from these patients with those from normal controls from previous studies. In myotonic dystrophy type 1 patients, the dose-response curve obtained with acceleromyography was steeper and right-shifted compared with that obtained using mechanomyography. However, the effective doses to produce 95% neuromuscular block determined with both acceleromyography and mechanomyography were similar to each other and to values found in normal patients. In the three myotonic dystrophy type 1 patients with mild to moderate disease, times to recovery from block were similar to those observed in normal controls. In both patients and normal controls, neuromuscular block recovered faster with acceleromyography. However, in one patient with severe muscle wasting, recovery of neuromuscular block was prolonged. We conclude that mechanomyography and acceleromyography cannot be used interchangeably to monitor neuromuscular block in myotonic dystrophy type 1 patients.

  15. Reliability and feasibility of the six minute walk test in subjects with myotonic dystrophy.

    PubMed

    Kierkegaard, Marie; Tollbäck, Anna

    2007-12-01

    The objective was to describe test-retest reliability and feasibility of the six minute walk test in adult subjects with myotonic dystrophy type 1. Twelve subjects (28-68 years, mean 44) performed three six minute walk tests on two occasions, one week apart. Relative reliability was high (ICC(2.1)=0.99) and absolute reliability values were low (standard error of measurement 12 m, repeatability 33 m). Feasibility was investigated in a sample of 64 subjects (19-70 years, mean 43). Fifty-two subjects were able to perform two tests on the same day. Subjects with severe proximal weakness had difficulties performing repeated tests. A practice trial followed by a second test on the same day can be recommended for most subjects, and the best test should be used for evaluations. In conclusion, even though the study sample was small, the present study indicates that the six minute walk test is reliable and feasible in subjects with myotonic dystrophy type 1.

  16. Analysis of meiotic segregation, using single-sperm typing: Meiotic drive at the myotonic dystrophy locus

    SciTech Connect

    Leeflang, E.P.; Arnheim, N.; McPeek, M.S.

    1996-10-01

    Meiotic drive at the myotonic dystrophy (DM) locus has recently been suggested as being responsible for maintaining the frequency, in the human population, of DM chromosomes capable of expansion to the disease state. In order to test this hypothesis, we have studied samples of single sperm from three individuals heterozygous at the DM locus, each with one allele larger and one allele smaller than 19 CTG repeats. To guard against the possible problem of differential PCR amplification rates based on the lengths of the alleles, the sperm were also typed at another closely linked marker whose allele size was unrelated to the allele size at the DM locus. Using statistical models specifically designed to study single-sperm segregation data, we find no evidence of meiotic segregation distortion. The upper limit of the two-sided 95% confidence interval for the estimate of the common segregation probability for the three donors is at or below .515 for all models considered, and no statistically significant difference from .5 is detected in any of the models. This suggests that any greater amount of segregation distortion at the myotonic dystrophy locus must result from events following sperm ejaculation. The mathematical models developed make it possible to study segregation distortion with high resolution by using sperm-typing data from any locus. 26 refs., 1 fig., 8 tabs.

  17. Oral motor movements and swallowing in patients with myotonic dystrophy type 1.

    PubMed

    Ercolin, Beatriz; Sassi, Fernanda Chiarion; Mangilli, Laura Davison; Mendonça, Lucia Iracema Zanotto; Limongi, Suelly Cecilia Olivan; de Andrade, Claudia Regina Furquim

    2013-09-01

    Oropharyngeal dysphagia and esophageal motility disorders were found to be the most important causes of aspiration pneumonia in patients with myotonic dystrophy. The purpose of this report was to evaluate clinical characteristics of the oral motor movements and swallowing of individuals with myotonic dystrophy type 1 (DM1) using a standardized clinical protocol and surface electromyography (sEMG). Participants were 40 individuals divided in two groups: G1 composed of 20 adults with DM1 and G2 composed of 20 healthy volunteers paired by age and gender to the individuals in G1. Statistical analysis included one-way ANOVA with two factors for within- and between-group comparisons and Bonferroni correction for multiple comparisons. Patients with DM1 presented deficits in posture, position, and mobility of the oral motor structures, as well as compromised mastication and deglutition. The sEMG data indicated that these patients had longer muscle activations during swallowing events. The longer duration of sEMG in the group of patients with DM1 is possibly related to myotonia and/or incoordination of the muscles involved in the swallowing process or could reflect a physiological adaptation for safe swallowing.

  18. How genetics affects the brain to produce higher-level dysfunctions in myotonic dystrophy type 1.

    PubMed

    Serra, Laura; Petrucci, Antonio; Spanò, Barbara; Torso, Mario; Olivito, Giusy; Lispi, Ludovico; Costanzi-Porrini, Sandro; Giulietti, Giovanni; Koch, Giacomo; Giacanelli, Manlio; Caltagirone, Carlo; Cercignani, Mara; Bozzali, Marco

    2015-01-01

    Myotonic dystrophy type 1 (DM1) is a multisystemic disorder dominated by muscular impairment and brain dysfunctions. Although brain damage has previously been demonstrated in DM1, its associations with the genetics and clinical/neuropsychological features of the disease are controversial. This study assessed the differential role of gray matter (GM) and white matter (WM) damage in determining higher-level dysfunctions in DM1. Ten patients with genetically confirmed DM1 and 16 healthy How genetics affects the brain to produce higher-level dysfunctions in myotonic dystrophy type 1 matched controls entered the study. The patients underwent a neuropsychological assessment and quantification of CTG triplet expansion. All the subjects underwent MR scanning at 3T, with studies including T1-weighted volumes and diffusion-weighted images. Voxel-based morphometry and tractbased spatial statistics were used for unbiased quantification of regional GM atrophy and WM integrity. The DM1 patients showed widespread involvement of both tissues. The extent of the damage correlated with CTG triplet expansion and cognition. This study supports the idea that genetic abnormalities in DM1mainly target the WM, but GM involvement is also crucial in determining the clinical characteristics of DM1.

  19. Dose-Dependent Regulation of Alternative Splicing by MBNL Proteins Reveals Biomarkers for Myotonic Dystrophy

    PubMed Central

    Struck, Adam J.; Gupta, Riti; Farnsworth, Dylan R.; Mahady, Amy E.; Eichinger, Katy; Thornton, Charles A.; Wang, Eric T.; Berglund, J. Andrew

    2016-01-01

    Alternative splicing is a regulated process that results in expression of specific mRNA and protein isoforms. Alternative splicing factors determine the relative abundance of each isoform. Here we focus on MBNL1, a splicing factor misregulated in the disease myotonic dystrophy. By altering the concentration of MBNL1 in cells across a broad dynamic range, we show that different splicing events require different amounts of MBNL1 for half-maximal response, and respond more or less steeply to MBNL1. Motifs around MBNL1 exon 5 were studied to assess how cis-elements mediate the MBNL1 dose-dependent splicing response. A framework was developed to estimate MBNL concentration using splicing responses alone, validated in the cell-based model, and applied to myotonic dystrophy patient muscle. Using this framework, we evaluated the ability of individual and combinations of splicing events to predict functional MBNL concentration in human biopsies, as well as their performance as biomarkers to assay mild, moderate, and severe cases of DM. PMID:27681373

  20. Pigmentation phenotype, photosensitivity and skin neoplasms in patients with myotonic dystrophy.

    PubMed

    Gadalla, S M; Hilbert, J E; Martens, W B; Givens, S; Moxley, R T; Greene, M H

    2017-05-01

    Recent studies have suggested a possible excess risk of skin neoplasms in patients with myotonic dystrophy (DM). Risk factors related to this observation have not been defined. Information regarding personal history of skin tumors, pigmentation phenotype, and skin reaction to sun exposure were collected from 266 DM patients who were enrolled in the US National Institutes of Health National Registry of Myotonic Dystrophy and Facioscapulohumeral Muscular Dystrophy Patients and Family Members. Seventy-seven subjects reported having skin tumors that were either benign (n = 31), malignant (n = 32) or both (n = 14). Female gender [odds ratio (OR) = 2.27, 95% confidence interval (CI) 1.02-5.05, P = 0.04], older age (OR = 1.10, 95% CI 1.05-1.16, P < 0.001) and DM1 subtype (OR = 3.42, 95% CI 1.27-9.26, P = 0.02) were associated with a malignant skin tumor. The associations between malignant skin tumors and known risk factors [light eye color (OR = 1.62, 95% CI 0.78-3.39, P = 0.20), light skin complexion (OR = 1.31, 95% CI 0.63-2.73, P = 0.48) and moderate/extensive face freckles (OR = 1.47, 95% CI 0.50-4.34, P = 0.49)] were modest. Strong, but not statistically significant, associations were noted with sunburn reactions when exposed to sunlight (OR = 4.28, 95% CI 0.91-19.95, P = 0.06, and OR = 2.19, 95% CI 0.67-7.09, P = 0.19, for sunburn with and without blistering, respectively). Although our study was limited by small sample size, the risk factors for malignant skin tumors in DM strongly resemble the general population. It is recommended that DM patients adhere to sun exposure protective behavior. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  1. Consensus statement on standard of care for congenital muscular dystrophies.

    PubMed

    Wang, Ching H; Bonnemann, Carsten G; Rutkowski, Anne; Sejersen, Thomas; Bellini, Jonathan; Battista, Vanessa; Florence, Julaine M; Schara, Ulrike; Schuler, Pamela M; Wahbi, Karim; Aloysius, Annie; Bash, Robert O; Béroud, Christophe; Bertini, Enrico; Bushby, Kate; Cohn, Ronald D; Connolly, Anne M; Deconinck, Nicolas; Desguerre, Isabelle; Eagle, Michelle; Estournet-Mathiaud, Brigitte; Ferreiro, Ana; Fujak, Albert; Goemans, Nathalie; Iannaccone, Susan T; Jouinot, Patricia; Main, Marion; Melacini, Paola; Mueller-Felber, Wolfgang; Muntoni, Francesco; Nelson, Leslie L; Rahbek, Jes; Quijano-Roy, Susana; Sewry, Caroline; Storhaug, Kari; Simonds, Anita; Tseng, Brian; Vajsar, Jiri; Vianello, Andrea; Zeller, Reinhard

    2010-12-01

    Congenital muscular dystrophies are a group of rare neuromuscular disorders with a wide spectrum of clinical phenotypes. Recent advances in understanding the molecular pathogenesis of congenital muscular dystrophy have enabled better diagnosis. However, medical care for patients with congenital muscular dystrophy remains very diverse. Advances in many areas of medical technology have not been adopted in clinical practice. The International Standard of Care Committee for Congenital Muscular Dystrophy was established to identify current care issues, review literature for evidence-based practice, and achieve consensus on care recommendations in 7 areas: diagnosis, neurology, pulmonology, orthopedics/rehabilitation, gastroenterology/ nutrition/speech/oral care, cardiology, and palliative care. To achieve consensus on the care recommendations, 2 separate online surveys were conducted to poll opinions from experts in the field and from congenital muscular dystrophy families. The final consensus was achieved in a 3-day workshop conducted in Brussels, Belgium, in November 2009. This consensus statement describes the care recommendations from this committee.

  2. Consensus Statement on Standard of Care for Congenital Muscular Dystrophies

    PubMed Central

    Wang, Ching H.; Bonnemann, Carsten G.; Rutkowski, Anne; Sejersen, Thomas; Bellini, Jonathan; Battista, Vanessa; Florence, Julaine M.; Schara, Ulrike; Schuler, Pamela M.; Wahbi, Karim; Aloysius, Annie; Bash, Robert O.; Béroud, Christophe; Bertini, Enrico; Bushby, Kate; Cohn, Ronald D.; Connolly, Anne M.; Deconinck, Nicolas; Desguerre, Isabelle; Eagle, Michelle; Estournet-Mathiaud, Brigitte; Ferreiro, Ana; Fujak, Albert; Goemans, Nathalie; Iannaccone, Susan T.; Jouinot, Patricia; Main, Marion; Melacini, Paola; Mueller-Felber, Wolfgang; Muntoni, Francesco; Nelson, Leslie L.; Rahbek, Jes; Quijano-Roy, Susana; Sewry, Caroline; Storhaug, Kari; Simonds, Anita; Tseng, Brian; Vajsar, Jiri; Vianello, Andrea; Zeller, Reinhard

    2016-01-01

    Congenital muscular dystrophies are a group of rare neuromuscular disorders with a wide spectrum of clinical phenotypes. Recent advances in understanding the molecular pathogenesis of congenital muscular dystrophy have enabled better diagnosis. However, medical care for patients with congenital muscular dystrophy remains very diverse. Advances in many areas of medical technology have not been adopted in clinical practice. The International Standard of Care Committee for Congenital Muscular Dystrophy was established to identify current care issues, review literature for evidence-based practice, and achieve consensus on care recommendations in 7 areas: diagnosis, neurology, pulmonology, orthopedics/rehabilitation, gastroenterology/ nutrition/speech/oral care, cardiology, and palliative care. To achieve consensus on the care recommendations, 2 separate online surveys were conducted to poll opinions from experts in the field and from congenital muscular dystrophy families. The final consensus was achieved in a 3-day workshop conducted in Brussels, Belgium, in November 2009. This consensus statement describes the care recommendations from this committee. PMID:21078917

  3. Parental age effects, but no evidence for an intrauterine effect in the transmission of myotonic dystrophy type 1.

    PubMed

    Morales, Fernando; Vásquez, Melissa; Cuenca, Patricia; Campos, Domingo; Santamaría, Carolina; Del Valle, Gerardo; Brian, Roberto; Sittenfeld, Mauricio; Monckton, Darren G

    2015-05-01

    Myotonic dystrophy type 1 (DM1) is caused by the expansion of an unstable CTG repeat (g.17294_17296(45_1000)) with more repeats associated with increased disease severity and reduced age at onset. Expanded disease-associated alleles are highly unstable in both the germline and soma. Germline instability is expansion biased, providing a molecular explanation for anticipation. Somatic instability is expansion biased, size- and age-dependent, features that have compromised genotype-phenotype correlations and intergenerational studies. We corrected these confounding factors by estimating the progenitor allele length in 54 father-offspring and 52 mother-offspring pairs in Costa Rican DM1 families. Not surprisingly, we found major parental allele length effects on the size of the allele transmitted, the magnitude of the intergenerational length change, the age at onset in the next generation and the degree of anticipation in both male and female transmissions. We also detected, for the first time, an age-of-parent effect for both male and female transmission. Interestingly, we found no evidence for an intrauterine effect in the transmission of congenital DM1, suggesting previous reports may have been an artefact of age-dependent somatic instability and sampling bias. These data provide new insights into the germline dynamics of the CTG repeat and opportunities for providing additional advice and more accurate risk assessments to prospective parents in DM1 families.

  4. Parental age effects, but no evidence for an intrauterine effect in the transmission of myotonic dystrophy type 1

    PubMed Central

    Morales, Fernando; Vásquez, Melissa; Cuenca, Patricia; Campos, Domingo; Santamaría, Carolina; del Valle, Gerardo; Brian, Roberto; Sittenfeld, Mauricio; Monckton, Darren G

    2015-01-01

    Myotonic dystrophy type 1 (DM1) is caused by the expansion of an unstable CTG repeat (g.17294_17296(45_1000)) with more repeats associated with increased disease severity and reduced age at onset. Expanded disease-associated alleles are highly unstable in both the germline and soma. Germline instability is expansion biased, providing a molecular explanation for anticipation. Somatic instability is expansion biased, size- and age-dependent, features that have compromised genotype–phenotype correlations and intergenerational studies. We corrected these confounding factors by estimating the progenitor allele length in 54 father–offspring and 52 mother–offspring pairs in Costa Rican DM1 families. Not surprisingly, we found major parental allele length effects on the size of the allele transmitted, the magnitude of the intergenerational length change, the age at onset in the next generation and the degree of anticipation in both male and female transmissions. We also detected, for the first time, an age-of-parent effect for both male and female transmission. Interestingly, we found no evidence for an intrauterine effect in the transmission of congenital DM1, suggesting previous reports may have been an artefact of age-dependent somatic instability and sampling bias. These data provide new insights into the germline dynamics of the CTG repeat and opportunities for providing additional advice and more accurate risk assessments to prospective parents in DM1 families. PMID:25052313

  5. Celf1 regulates cell cycle and is partially responsible for defective myoblast differentiation in myotonic dystrophy RNA toxicity.

    PubMed

    Peng, Xiaoping; Shen, Xiaopeng; Chen, Xuanying; Liang, Rui; Azares, Alon R; Liu, Yu

    2015-07-01

    Myotonic dystrophy is a neuromuscular disease of RNA toxicity. The disease gene DMPK harbors expanded CTG trinucleotide repeats on its 3'-UTR. The transcripts of this mutant DMPK led to misregulation of RNA-binding proteins including MBNL1 and Celf1. In myoblasts, CUG-expansion impaired terminal differentiation. In this study, we formally tested how the abundance of Celf1 regulates normal myocyte differentiation, and how Celf1 expression level mediates CUG-expansion RNA toxicity-triggered impairment of myocyte differentiation. As the results, overexpression of Celf1 largely recapitulated the defects of myocytes with CUG-expansion, by increasing myocyte cycling. Knockdown of endogenous Celf1 level led to precocious myotube formation, supporting a negative connection between Celf1 abundance and myocyte terminal differentiation. Finally, knockdown of Celf1 in myocyte with CUG-expansion led to partial rescue, by promoting cell cycle exit. Our results suggest that Celf1 plays a distinctive and negative role in terminal myocyte differentiation, which partially contribute to DM1 RNA toxicity. Targeting Celf1 may be a valid strategy in correcting DM1 muscle phenotypes, especially for congenital cases. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Genetics Home Reference: T-cell immunodeficiency, congenital alopecia, and nail dystrophy

    MedlinePlus

    ... alopecia, and nail dystrophy T-cell immunodeficiency, congenital alopecia, and nail dystrophy Printable PDF Open All Close ... expand/collapse boxes. Description T-cell immunodeficiency, congenital alopecia, and nail dystrophy is a type of severe ...

  7. TWEAK/Fn14, a pathway and novel therapeutic target in myotonic dystrophy.

    PubMed

    Yadava, Ramesh S; Foff, Erin P; Yu, Qing; Gladman, Jordan T; Kim, Yun K; Bhatt, Kirti S; Thornton, Charles A; Zheng, Timothy S; Mahadevan, Mani S

    2015-04-01

    Myotonic dystrophy type 1 (DM1), the most prevalent muscular dystrophy in adults, is characterized by progressive muscle wasting and multi-systemic complications. DM1 is the prototype for disorders caused by RNA toxicity. Currently, no therapies exist. Here, we identify that fibroblast growth factor-inducible 14 (Fn14), a member of the tumor necrosis factor receptor super-family, is induced in skeletal muscles and hearts of mouse models of RNA toxicity and in tissues from DM1 patients, and that its expression correlates with severity of muscle pathology. This is associated with downstream signaling through the NF-κB pathways. In mice with RNA toxicity, genetic deletion of Fn14 results in reduced muscle pathology and better function. Importantly, blocking TWEAK/Fn14 signaling with an anti-TWEAK antibody likewise improves muscle histopathology and functional outcomes in affected mice. These results reveal new avenues for therapeutic development and provide proof of concept for a novel therapeutic target for which clinically available therapy exists to potentially treat muscular dystrophy in DM1.

  8. Modifications to toxic CUG RNAs induce structural stability, rescue mis-splicing in a myotonic dystrophy cell model and reduce toxicity in a myotonic dystrophy zebrafish model

    DOE PAGES

    deLorimier, Elaine; Coonrod, Leslie A.; Copperman, Jeremy; ...

    2014-10-10

    In this study, CUG repeat expansions in the 3' UTR of dystrophia myotonica protein kinase (DMPK) cause myotonic dystrophy type 1 (DM1). As RNA, these repeats elicit toxicity by sequestering splicing proteins, such as MBNL1, into protein–RNA aggregates. Structural studies demonstrate that CUG repeats can form A-form helices, suggesting that repeat secondary structure could be important in pathogenicity. To evaluate this hypothesis, we utilized structure-stabilizing RNA modifications pseudouridine (Ψ) and 2'-O-methylation to determine if stabilization of CUG helical conformations affected toxicity. CUG repeats modified with Ψ or 2'-O-methyl groups exhibited enhanced structural stability and reduced affinity for MBNL1. Molecular dynamicsmore » and X-ray crystallography suggest a potential water-bridging mechanism for Ψ-mediated CUG repeat stabilization. Ψ modification of CUG repeats rescued mis-splicing in a DM1 cell model and prevented CUG repeat toxicity in zebrafish embryos. This study indicates that the structure of toxic RNAs has a significant role in controlling the onset of neuromuscular diseases.« less

  9. Modifications to toxic CUG RNAs induce structural stability, rescue mis-splicing in a myotonic dystrophy cell model and reduce toxicity in a myotonic dystrophy zebrafish model

    SciTech Connect

    deLorimier, Elaine; Coonrod, Leslie A.; Copperman, Jeremy; Taber, Alex; Reister, Emily E.; Sharma, Kush; Todd, Peter K.; Guenza, Marina G.; Berglund, J. Andrew

    2014-10-10

    In this study, CUG repeat expansions in the 3' UTR of dystrophia myotonica protein kinase (DMPK) cause myotonic dystrophy type 1 (DM1). As RNA, these repeats elicit toxicity by sequestering splicing proteins, such as MBNL1, into protein–RNA aggregates. Structural studies demonstrate that CUG repeats can form A-form helices, suggesting that repeat secondary structure could be important in pathogenicity. To evaluate this hypothesis, we utilized structure-stabilizing RNA modifications pseudouridine (Ψ) and 2'-O-methylation to determine if stabilization of CUG helical conformations affected toxicity. CUG repeats modified with Ψ or 2'-O-methyl groups exhibited enhanced structural stability and reduced affinity for MBNL1. Molecular dynamics and X-ray crystallography suggest a potential water-bridging mechanism for Ψ-mediated CUG repeat stabilization. Ψ modification of CUG repeats rescued mis-splicing in a DM1 cell model and prevented CUG repeat toxicity in zebrafish embryos. This study indicates that the structure of toxic RNAs has a significant role in controlling the onset of neuromuscular diseases.

  10. SCN4A mutation as modifying factor of myotonic dystrophy type 2 phenotype.

    PubMed

    Bugiardini, E; Rivolta, I; Binda, A; Soriano Caminero, A; Cirillo, F; Cinti, A; Giovannoni, R; Botta, A; Cardani, R; Wicklund, M P; Meola, G

    2015-04-01

    In myotonic dystrophy type 2 (DM2), an association has been reported between early and severe myotonia and recessive chloride channel (CLCN1) mutations. No DM2 cases have been described with sodium channel gene (SCN4A) mutations. The aim is to describe a DM2 patient with severe and early onset myotonia and co-occurrence of a novel missense mutation in SNC4A. A 26-year-old patient complaining of hand cramps and difficulty relaxing her hands after activity was evaluated at our department. Neurophysiology and genetic analysis for DM1, DM2, CLCN1 and SCN4A mutations were performed. Genetic testing was positive for DM2 (2650 CCTG repeat) and for a variant c.215C>T (p.Pro72Leu) in the SCN4A gene. The variation affects the cytoplasmic N terminus domain of Nav1.4, where mutations have never been reported. The biophysical properties of the mutant Nav1.4 channels were evaluated by whole-cell voltage-clamp analysis of heterologously expressed mutant channel in tsA201 cells. Electrophysiological studies of the P72L variant showed a hyperpolarizing shift (-5 mV) of the voltage dependence of activation that may increase cell excitability. This case suggests that SCN4A mutations may enhance the myotonic phenotype of DM2 patients and should be screened for atypical cases with severe myotonia.

  11. Homozygous myotonic dystrophy: clinical and molecular studies of three unrelated cases.

    PubMed Central

    Martorell, L; Illa, I; Rosell, J; Benitez, J; Sedano, M J; Baiget, M

    1996-01-01

    We report the clinical and molecular study of three unrelated homozygous myotonic dystrophy patients. In the first family, the homozygous patient shows the classical form of the disease with two DM alleles of very different expansion sizes (1000 and 60 repeats). In the second family, the homozygous patient is mildly affected and carries a minimally expanded allele (64 repeats) and a "normal" allele (38 repeats) that increases in size when transmitted. Such an intergenerational expansion of an allele in this range of repeats has not been reported to date. The third homozygous case has late onset bilateral cataracts as the only symptom. She has two minimally expanded alleles (51 and 120 repeats) that showed different intergenerational enlargement during transmission to the next generation. Images PMID:8880582

  12. Infant mortality in myotonic dystrophy in Saguenay-Lac-St-Jean: a historical perspective.

    PubMed

    Dao, T N; Mathieu, J; Bouchard, J P; De Braekeleer, M

    1993-01-01

    Infant mortality among children born to 373 individuals with myotonic dystrophy (MD) who lived in Saguenay-Lac-St-Jean during the period 1838 to the present time was analyzed using a case-control approach based on a population register. A statistically significant increase was found in the rate of deaths during the first week of life among children born to MD mothers (57.5%) compared to control mothers (34.8%) and MD fathers (39.1%) (p < 0.01). The stillbirth rate was not increased. The rate of mortality after the first week fell significantly in both MD and control groups during the period of observation. There was evidence of a slight selective disadvantage among this MD population.

  13. Fatigue and daytime sleepiness in patients with myotonic dystrophy type 1: to lump or split?

    PubMed

    Laberge, Luc; Dauvilliers, Yves; Bégin, Paul; Richer, Louis; Jean, Stéphane; Mathieu, Jean

    2009-06-01

    We assessed the relationship and clinical correlates of fatigue and Excessive Daytime Sleepiness (EDS) in 200 myotonic dystrophy type 1 (DM1) patients by means of questionnaire and neuropsychological evaluation. Fatigue levels were higher in patients with EDS and daytime sleepiness levels higher in patients with excessive fatigue. However, EDS without fatigue was rarely observed. Also, DM1 patients with fatigue (with or without EDS) showed greater muscular impairment, CTG repeats, abnormalities regarding personality, depressive symptoms and lower health-related quality of life (HRQoL) than patients without these symptoms. These findings do not readily support the contention that fatigue and EDS constitute distinct clinical manifestations in DM1. Clinicians should systematically evaluate both symptoms since fatigue and EDS have a greater impact on HRQoL than fatigue alone. However, specific rating scales for fatigue in DM1 have yet to be devised.

  14. The effect of myotonic dystrophy transcript levels and location on muscle differentiation

    SciTech Connect

    Mastroyiannopoulos, Nikolaos P.; Chrysanthou, Elina; Kyriakides, Tassos C.; Uney, James B.; Mahadevan, Mani S.; Phylactou, Leonidas A.

    2008-12-12

    In myotonic dystrophy type I (DM1), nuclear retention of mutant DMPK transcripts compromises muscle cell differentiation. Although several reports have identified molecular defects in myogenesis, it remains still unclear how exactly the retention of the mutant transcripts induces this defect. We have recently created a novel cellular model in which the mutant DMPK 3' UTR transcripts were released to the cytoplasm of myoblasts by using the WPRE genetic element. As a result, muscle cell differentiation was repaired. In this paper, this cellular model was further exploited to investigate the effect of the levels and location of the mutant transcripts on muscle differentiation. Results show that the levels of these transcripts were proportional to the inhibition of both the initial fusion of myoblasts and the maturity of myotubes. Moreover, the cytoplasmic export of the mutant RNAs to the cytoplasm caused less inhibition only in the initial fusion of myoblasts.

  15. Neuromuscular transmission abnormalities in myotonic dystrophy type 1: A neurophysiological study.

    PubMed

    Bombelli, Francesco; Lispi, Ludovico; Porrini, Sandro Costanzi; Giacanelli, Manlio; Terracciano, Chiara; Massa, Roberto; Petrucci, Antonio

    2016-11-01

    Weakness and fatigue are frequent symptoms in myotonic dystrophy type 1 (DM1), mainly as a result of muscle impairment. However, neuromuscular junction (NMJ) abnormalities could play an additional role in determining these manifestations. We aimed to document the possible NMJ involvement in DM1. In order to substantiate this hypothesis we performed low rate repetitive nerve stimulation (RNS) and single fiber electromyography (SFEMG), in 14 DM1 subjects. RNS resulted abnormal in four patients while SFEMG revealed a pathological jitter in ten. A significative correlation was found between jitter values and decrementing response (p<0.000311; r=0.822). These results suggest a possible involvement of NMJ in DM1. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Antisense Oligonucleotides: Rising Stars in Eliminating RNA Toxicity in Myotonic Dystrophy

    PubMed Central

    Gao, Zhihua

    2013-01-01

    Abstract Myotonic dystrophy (DM) is a dominantly inherited, multisystemic disease caused by expanded CTG (type 1, DM1) or CCTG (type 2, DM2) repeats in untranslated regions of the mutated genes. Pathogenesis results from expression of RNAs from the mutated alleles that are toxic because of the expanded CUG or CCUG repeats. Increased understanding of the repeat-containing RNA (C/CUGexp RNA)-induced toxicity has led to the development of multiple strategies targeting the toxic RNA. Among these approaches, antisense oligonucleotides (ASOs) have demonstrated high potency in reversing the RNA toxicity in both cultured DM1 cells and DM1 animal models, thus offering great promise for the potential treatment of DM1. ASO targeting approaches will also provide avenues for the treatment of other repeat RNA-mediated diseases. PMID:23252746

  17. MRI findings and cognitive functions in a small cohort of myotonic dystrophy type 1: Retrospective analyses.

    PubMed

    Bajrami, Arsida; Azman, Filiz; Yayla, Vildan; Cagirici, Sultan; Keskinkiliç, Cahit; Sozer, Nejla

    2017-02-01

    Myotonic dystrophy type 1 (DM1) is a progressive multisystemic disease with common cognitive deficits and potential brain involvement in addition to the cardinal muscular and systemic symptoms. Impaired mental function associated with nonspecific pathological findings such as white-matter hyperintense lesions (WMHLs), ventricular enlargement and brain atrophy on brain MRI have been previously reported in DM1 patients. While some studies showed correlation of brain morphological changes with neuropsychological and clinical parameters including CTG repeat sizes and disease severity scales in DM1, others failed. The goal of this study was to retrospectively investigate cranial MR abnormalities, predominantly WMHLs, and their effects on clinical and cognitive deficits in a small, phenotypically or genotypically well-characterized cohort of DM1 patients.

  18. Lower limb muscle impairment in myotonic dystrophy type 1: the need for better guidelines.

    PubMed

    Petitclerc, Émilie; Hébert, Luc J; Desrosiers, Johanne; Gagnon, Cynthia

    2015-04-01

    In myotonic dystrophy type 1 (DM1), leg muscle weakness is a major impairment. There are challenges to obtaining a clear portrait of muscle strength impairment. A systematic literature review was conducted on lower limb strength impairment in late-onset and adult phenotypes to document variables which affect strength measurement. Thirty-two articles were reviewed using the COSMIN guidelines. Only a third of the studies described a reproducible protocol. Only 2 muscle groups have documented reliability for quantitative muscle testing and only 1 total score for manual muscle testing. Variables affecting muscle strength impairment are not described in most studies. This review illustrates the variability in muscle strength assessment in relation to DM1 characteristics and the questionable validity of the results with regard to undocumented methodological properties. There is therefore a clear need to adopt a consensus on the use of a standardized muscle strength assessment protocol.

  19. Therapeutic impact of systemic AAV-mediated RNA interference in a mouse model of myotonic dystrophy

    PubMed Central

    Bisset, Darren R.; Stepniak-Konieczna, Ewa A.; Zavaljevski, Maja; Wei, Jessica; Carter, Gregory T.; Weiss, Michael D.; Chamberlain, Joel R.

    2015-01-01

    RNA interference (RNAi) offers a promising therapeutic approach for dominant genetic disorders that involve gain-of-function mechanisms. One candidate disease for RNAi therapy application is myotonic dystrophy type 1 (DM1), which results from toxicity of a mutant mRNA. DM1 is caused by expansion of a CTG repeat in the 3′ UTR of the DMPK gene. The expression of DMPK mRNA containing an expanded CUG repeat (CUGexp) leads to defects in RNA biogenesis and turnover. We designed miRNA-based RNAi hairpins to target the CUGexp mRNA in the human α-skeletal muscle actin long-repeat (HSALR) mouse model of DM1. RNAi expression cassettes were delivered to HSALR mice using recombinant adeno-associated viral (rAAV) vectors injected intravenously as a route to systemic gene therapy. Vector delivery significantly reduced disease pathology in muscles of the HSALR mice, including a reduction in the CUGexp mRNA, a reduction in myotonic discharges, a shift toward adult pre-mRNA splicing patterns, reduced myofiber hypertrophy and a decrease in myonuclear foci containing the CUGexp mRNA. Significant reversal of hallmarks of DM1 in the rAAV RNAi-treated HSALR mice indicate that defects characteristic of DM1 can be mitigated with a systemic RNAi approach targeting the nuclei of terminally differentiated myofibers. Efficient rAAV-mediated delivery of RNAi has the potential to provide a long-term therapy for DM1 and other dominant muscular dystrophies. PMID:26082468

  20. Gastrobronchial fistula following minimally invasive esophagectomy for esophageal cancer in a patient with myotonic dystrophy: Case report

    PubMed Central

    Hugin, Silje; Johnson, Egil; Johannessen, Hans-Olaf; Hofstad, Bjørn; Olafsen, Kjell; Mellem, Harald

    2015-01-01

    Introduction Myotonic dystrophies are inherited multisystemic diseases characterized by musculopathy, cardiac arrythmias and cognitive disorders. These patients are at increased risk for fatal post-surgical complications from pulmonary hypoventilation. We present a case with myotonic dystrophy and esophageal cancer who had a minimally invasive esophagectomy complicated with gastrobronchial fistulisation. Presentation of case A 44-year-old male with myotonic dystrophy type 1 and esophageal cancer had a minimally invasive esophagectomy performed instead of open surgery in order to reduce the risk for pulmonary complications. At day 15 respiratory failure occurred from a gastrobronchial fistula between the right intermediary bronchus (defect 7–8 mm) and the esophagogastric anastomosis (defect 10 mm). In order to minimize large leakage of air into the gastric conduit the anastomosis was stented and ventilation maintained at low airway pressures. His general condition improved and allowed extubation at day 29 and stent removal at day 35. Bronchoscopy confirmed that the fistula was healed. The patient was discharged from hospital at day 37 without further complications. Discussion The fistula was probably caused by bronchial necrosis from thermal injury during close dissection using the Ligasure instrument. Fistula treatment by non-surgical intervention was considered safer than surgery which could be followed by potentially life-threatening respiratory complications. Indications for stenting of gastrobronchial fistulas will be discussed. Conclusions Minimally invasive esophagectomy was performed instead of open surgery in a myotonic dystrophy patient as these patients are particularly vulnerable to respiratory complications. Gastrobronchial fistula, a major complication, was safely treated by stenting and low airway pressure ventilation. PMID:26520033

  1. Feasibility and effects of a physical exercise programme in adults with myotonic dystrophy type 1: a randomized controlled pilot study.

    PubMed

    Kierkegaard, Marie; Harms-Ringdahl, Karin; Edström, Lars; Widén Holmqvist, Lotta; Tollbäck, Anna

    2011-07-01

    To investigate the feasibility and effects of a physical exercise programme on functioning and health-related quality of life in adults with myotonic dystrophy type 1. A randomized controlled trial. Thirty-five adults with myotonic dystrophy type 1. After stratification for level of functioning, study participants were assigned by lot to either a training group or a control group. Training-group participants attended a 60-minute comprehensive group-training programme, Friskis&Svettis® Open Doors, twice a week for 14 weeks. The six-minute walk test was the primary outcome measure and the timed-stands test, the timed up-and-go test, the Epworth sleepiness scale and the Short Form-36 health survey were secondary outcome measures. Intention-to-treat analyses revealed no significant differences in any outcome measures, except for an increased between-group difference after intervention in the Short Form-36 mental health subscale and a decrease in the vitality subscale for the control group. The programme was well tolerated and many training-group participants perceived subjective changes for the better. No negative effects were reported. The Friskis&Svettis® Open Doors programme was feasible for adults with myotonic dystrophy type 1 who had been screened for cardiac involvement, had distal or mild-to-moderate proximal muscle impairment, and no severe cognitive impairments. No beneficial or detrimental effects were evident.

  2. Splicing misregulation of SCN5A contributes to cardiac-conduction delay and heart arrhythmia in myotonic dystrophy

    PubMed Central

    Freyermuth, Fernande; Rau, Frédérique; Kokunai, Yosuke; Linke, Thomas; Sellier, Chantal; Nakamori, Masayuki; Kino, Yoshihiro; Arandel, Ludovic; Jollet, Arnaud; Thibault, Christelle; Philipps, Muriel; Vicaire, Serge; Jost, Bernard; Udd, Bjarne; Day, John W.; Duboc, Denis; Wahbi, Karim; Matsumura, Tsuyoshi; Fujimura, Harutoshi; Mochizuki, Hideki; Deryckere, François; Kimura, Takashi; Nukina, Nobuyuki; Ishiura, Shoichi; Lacroix, Vincent; Campan-Fournier, Amandine; Navratil, Vincent; Chautard, Emilie; Auboeuf, Didier; Horie, Minoru; Imoto, Keiji; Lee, Kuang-Yung; Swanson, Maurice S.; de Munain, Adolfo Lopez; Inada, Shin; Itoh, Hideki; Nakazawa, Kazuo; Ashihara, Takashi; Wang, Eric; Zimmer, Thomas; Furling, Denis; Takahashi, Masanori P.; Charlet-Berguerand, Nicolas

    2016-01-01

    Myotonic dystrophy (DM) is caused by the expression of mutant RNAs containing expanded CUG repeats that sequester muscleblind-like (MBNL) proteins, leading to alternative splicing changes. Cardiac alterations, characterized by conduction delays and arrhythmia, are the second most common cause of death in DM. Using RNA sequencing, here we identify novel splicing alterations in DM heart samples, including a switch from adult exon 6B towards fetal exon 6A in the cardiac sodium channel, SCN5A. We find that MBNL1 regulates alternative splicing of SCN5A mRNA and that the splicing variant of SCN5A produced in DM presents a reduced excitability compared with the control adult isoform. Importantly, reproducing splicing alteration of Scn5a in mice is sufficient to promote heart arrhythmia and cardiac-conduction delay, two predominant features of myotonic dystrophy. In conclusion, misregulation of the alternative splicing of SCN5A may contribute to a subset of the cardiac dysfunctions observed in myotonic dystrophy. PMID:27063795

  3. Splicing misregulation of SCN5A contributes to cardiac-conduction delay and heart arrhythmia in myotonic dystrophy.

    PubMed

    Freyermuth, Fernande; Rau, Frédérique; Kokunai, Yosuke; Linke, Thomas; Sellier, Chantal; Nakamori, Masayuki; Kino, Yoshihiro; Arandel, Ludovic; Jollet, Arnaud; Thibault, Christelle; Philipps, Muriel; Vicaire, Serge; Jost, Bernard; Udd, Bjarne; Day, John W; Duboc, Denis; Wahbi, Karim; Matsumura, Tsuyoshi; Fujimura, Harutoshi; Mochizuki, Hideki; Deryckere, François; Kimura, Takashi; Nukina, Nobuyuki; Ishiura, Shoichi; Lacroix, Vincent; Campan-Fournier, Amandine; Navratil, Vincent; Chautard, Emilie; Auboeuf, Didier; Horie, Minoru; Imoto, Keiji; Lee, Kuang-Yung; Swanson, Maurice S; Lopez de Munain, Adolfo; Inada, Shin; Itoh, Hideki; Nakazawa, Kazuo; Ashihara, Takashi; Wang, Eric; Zimmer, Thomas; Furling, Denis; Takahashi, Masanori P; Charlet-Berguerand, Nicolas

    2016-04-11

    Myotonic dystrophy (DM) is caused by the expression of mutant RNAs containing expanded CUG repeats that sequester muscleblind-like (MBNL) proteins, leading to alternative splicing changes. Cardiac alterations, characterized by conduction delays and arrhythmia, are the second most common cause of death in DM. Using RNA sequencing, here we identify novel splicing alterations in DM heart samples, including a switch from adult exon 6B towards fetal exon 6A in the cardiac sodium channel, SCN5A. We find that MBNL1 regulates alternative splicing of SCN5A mRNA and that the splicing variant of SCN5A produced in DM presents a reduced excitability compared with the control adult isoform. Importantly, reproducing splicing alteration of Scn5a in mice is sufficient to promote heart arrhythmia and cardiac-conduction delay, two predominant features of myotonic dystrophy. In conclusion, misregulation of the alternative splicing of SCN5A may contribute to a subset of the cardiac dysfunctions observed in myotonic dystrophy.

  4. Targeting DMPK with Antisense Oligonucleotide Improves Muscle Strength in Myotonic Dystrophy Type 1 Mice.

    PubMed

    Jauvin, Dominic; Chrétien, Jessina; Pandey, Sanjay K; Martineau, Laurie; Revillod, Lucille; Bassez, Guillaume; Lachon, Aline; MacLeod, A Robert; Gourdon, Geneviève; Wheeler, Thurman M; Thornton, Charles A; Bennett, C Frank; Puymirat, Jack

    2017-06-16

    Myotonic dystrophy type 1 (DM1), a dominant hereditary muscular dystrophy, is caused by an abnormal expansion of a (CTG)n trinucleotide repeat in the 3' UTR of the human dystrophia myotonica protein kinase (DMPK) gene. As a consequence, mutant transcripts containing expanded CUG repeats are retained in nuclear foci and alter the function of splicing regulatory factors members of the MBNL and CELF families, resulting in alternative splicing misregulation of specific transcripts in affected DM1 tissues. In the present study, we treated DMSXL mice systemically with a 2'-4'-constrained, ethyl-modified (ISIS 486178) antisense oligonucleotide (ASO) targeted to the 3' UTR of the DMPK gene, which led to a 70% reduction in CUG(exp) RNA abundance and foci in different skeletal muscles and a 30% reduction in the heart. Furthermore, treatment with ISIS 486178 ASO improved body weight, muscle strength, and muscle histology, whereas no overt toxicity was detected. This is evidence that the reduction of CUG(exp) RNA improves muscle strength in DM1, suggesting that muscle weakness in DM1 patients may be improved following elimination of toxic RNAs. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Five-year study of quality of life in myotonic dystrophy.

    PubMed

    Peric, S; Vujnic, M; Dobricic, V; Marjanovic, A; Basta, I; Novakovic, I; Lavrnic, D; Rakocevic-Stojanovic, V

    2016-11-01

    Background - Myotonic dystrophy type 1 (DM1) is the most common muscular dystrophy in adults. There is a complete lack of studies that assessed quality of life (QoL) trajectory during time in DM1 cohorts. Aim - To analyze changes of QoL in patients with DM1 during a 5-year follow-up period and to assess responsiveness of the SF-36 questionnaire. Patients and Method - At the baseline, this study comprised 84 DM1 patients, of whom 62 were retested after the mean period of 64.2 ± 3.9 months. Severity of muscular weakness was assessed using the Muscular Impairment Rating Scale (MIRS). Patients completed Serbian version of the SF-36 questionnaire as a measure of health-related QoL. Results - After 5 years, MIRS score of our DM1 patients showed significant progression of 0.5 grade (P < 0.01). All mental subdomains, role physical, and total SF-36 scores significantly improved after 5 years (P < 0.01). Unexpectedly, worsening of muscular weakness from mild to severe was in association with improvement of QoL. Conclusion - QoL improved in our cohort of DM1 patients during a 5-year period despite the progression of the disease. SF-36 should be used with caution as a patient-reported outcome measure in DM1 clinical trials.

  6. Mis-splicing of Tau exon 10 in myotonic dystrophy type 1 is reproduced by overexpression of CELF2 but not by MBNL1 silencing.

    PubMed

    Dhaenens, C M; Tran, H; Frandemiche, M-L; Carpentier, C; Schraen-Maschke, S; Sistiaga, A; Goicoechea, M; Eddarkaoui, S; Van Brussels, E; Obriot, H; Labudeck, A; Gevaert, M H; Fernandez-Gomez, F; Charlet-Berguerand, N; Deramecourt, V; Maurage, C A; Buée, L; Lopez de Munain, A; Sablonnière, B; Caillet-Boudin, M L; Sergeant, N

    2011-07-01

    Tau is the proteinaceous component of intraneuronal aggregates common to neurodegenerative diseases called Tauopathies, including myotonic dystrophy type 1. In myotonic dystrophy type 1, the presence of microtubule-associated protein Tau aggregates is associated with a mis-splicing of Tau. A toxic gain-of-function at the ribonucleic acid level is a major etiological factor responsible for the mis-splicing of several transcripts in myotonic dystrophy type 1. These are probably the consequence of a loss of muscleblind-like 1 (MBNL1) function or gain of CUGBP1 and ETR3-like factor 1 (CELF1) splicing function. Whether these two dysfunctions occur together or separately and whether all mis-splicing events in myotonic dystrophy type 1 brain result from one or both of these dysfunctions remains unknown. Here, we analyzed the splicing of Tau exons 2 and 10 in the brain of myotonic dystrophy type 1 patients. Two myotonic dystrophy type 1 patients showed a mis-splicing of exon 10 whereas exon 2-inclusion was reduced in all myotonic dystrophy type 1 patients. In order to determine the potential factors responsible for exon 10 mis-splicing, we studied the effect of the splicing factors muscleblind-like 1 (MBNL1), CUGBP1 and ETR3-like factor 1 (CELF1), CUGBP1 and ETR3-like factor 2 (CELF2), and CUGBP1 and ETR3-like factor 4 (CELF4) or a dominant-negative CUGBP1 and ETR-3 like factor (CELF) factor on Tau exon 10 splicing by ectopic expression or siRNA. Interestingly, the inclusion of Tau exon 10 is reduced by CUGBP1 and ETR3-like factor 2 (CELF2) whereas it is insensitive to the loss-of-function of muscleblind-like 1 (MBNL1), CUGBP1 and ETR3-like factor 1 (CELF1) gain-of-function, or a dominant-negative of CUGBP1 and ETR-3 like factor (CELF) factor. Moreover, we observed an increased expression of CUGBP1 and ETR3-like factor 2 (CELF2) only in the brain of myotonic dystrophy type 1 patients with a mis-splicing of exon 10. Taken together, our results indicate the occurrence of a

  7. Relationship of white and gray matter abnormalities to clinical and genetic features in myotonic dystrophy type 1.

    PubMed

    Zanigni, Stefano; Evangelisti, Stefania; Giannoccaro, Maria Pia; Oppi, Federico; Poda, Roberto; Giorgio, Antonio; Testa, Claudia; Manners, David Neil; Avoni, Patrizia; Gramegna, Laura Ludovica; De Stefano, Nicola; Lodi, Raffaele; Tonon, Caterina; Liguori, Rocco

    2016-01-01

    Myotonic dystrophy type 1 (DM1) represents a multisystemic disorder in which diffuse brain white and gray matter alterations related to clinical and genetic features have been described. We aimed to evaluate in the brain of adult patients with DM1 (i) white and gray matter differences, including cortical-subcortical gray matter volume and cortical thickness and (ii) their correlation with clinical disability, global neuropsychological performance and triplet expansion. We included 24 adult genetically-confirmed DM1 patients (14 males; age: 38.5 ± 11.8 years) and 25 age- and sex-matched healthy controls (14 males; age: 38.5 ± 11.3 years) who underwent an identical brain MR protocol including high-resolution 3D T1-weighted, axial T2 FLAIR and DTI sequences. All patients underwent an extensive clinical and neuropsychological evaluation. Voxel-wise analyses of white matter, performed by using Tract Based Spatial Statistics, and of gray matter, with Voxel-based Morphometry and Cortical Thickness, were carried out in order to test for differences between patients with DM1 and healthy controls (p < 0.05, corrected). The correlation between MRI measures and clinical-genetic features was also assessed. Patients with DM1 showed widespread abnormalities of all DTI parameters in the white matter, which were associated with reduced gray matter volume in all brain lobes and thinning in parieto-temporo-occipital cortices, albeit with less extensive cortical alterations when congenital cases were removed from the analyses. White matter alterations correlated with clinical disability, global cognitive performance and triplet expansions. In patients with DM1, the combined smaller overall gray matter volume and white matter alterations seem to be the main morpho-structural substrates of CNS involvement in this condition. The correlation of white matter differences with both clinical and genetic findings lends support to this notion.

  8. Unravelling the myotonic dystrophy type 1 clinical spectrum: A systematic registry-based study with implications for disease classification.

    PubMed

    De Antonio, M; Dogan, C; Hamroun, D; Mati, M; Zerrouki, S; Eymard, B; Katsahian, S; Bassez, G

    2016-10-01

    The broad clinical spectrum of myotonic dystrophy type 1 (DM1) creates particular challenges for both medical care and design of clinical trials. Clinical onset spans a continuum from birth to late adulthood, with symptoms that are highly variable in both severity and nature of the affected organ systems. In the literature, this complex phenotype is divided into three grades (mild, classic, and severe) and four or five main clinical categories (congenital, infantile/juvenile, adult-onset and late-onset forms), according to symptom severity and age of onset, respectively. However, these classifications are still under discussion with no consensus thus far. While some specific clinical features have been primarily reported in some forms of the disease, there are no clear distinctions. As a consequence, no modifications in the management of healthcare or the design of clinical studies have been proposed based on the clinical form of DM1. The present study has used the DM-Scope registry to assess, in a large cohort of DM1 patients, the robustness of a classification divided into five clinical forms. Our main aim was to describe the disease spectrum and investigate features of each clinical form. The five subtypes were compared by distribution of CTG expansion size, and the occurrence and onset of the main symptoms of DM1. Analyses validated the relevance of a five-grade model for DM1 classification. Patients were classified as: congenital (n=93, 4.5%); infantile (n=303, 14.8%); juvenile (n=628, 30.7%); adult (n=694, 34.0%); and late-onset (n=326, 15.9%). Our data show that the assumption of a continuum from congenital to the late-onset form is valid, and also highlights disease features specific to individual clinical forms of DM1 in terms of symptom occurrence and chronology throughout the disease course. These results support the use of the five-grade model for disease classification, and the distinct clinical profiles suggest that age of onset and clinical form may

  9. Using digital technologies to engage with medical research: views of myotonic dystrophy patients in Japan.

    PubMed

    Coathup, Victoria; Teare, Harriet J A; Minari, Jusaku; Yoshizawa, Go; Kaye, Jane; Takahashi, Masanori P; Kato, Kazuto

    2016-08-24

    As in other countries, the traditional doctor-patient relationship in the Japanese healthcare system has often been characterised as being of a paternalistic nature. However, in recent years there has been a gradual shift towards a more participatory-patient model in Japan. With advances in technology, the possibility to use digital technologies to improve patient interactions is growing and is in line with changing attitudes in the medical profession and society within Japan and elsewhere. The implementation of an online patient engagement platform is being considered by the Myotonic Dystrophy Registry of Japan. The aim of this exploratory study was to understand patients' views and attitudes to using digital tools in patient registries and engagement with medical research in Japan, prior to implementation of the digital platform. We conducted an exploratory, cross-sectional, self-completed questionnaire with a sample of myotonic dystrophy (MD) patients attending an Open Day at Osaka University, Japan. Patients were eligible for inclusion if they were 18 years or older, and were diagnosed with MD. A total of 68 patients and family members attended the Open Day and were invited to participate in the survey. Of those, 59 % submitted a completed questionnaire (n = 40). The survey showed that the majority of patients felt that they were not receiving the information they wanted from their clinicians, which included recent medical research findings and opportunities to participate in clinical trials, and 88 % of patients indicated they would be willing to engage with digital technologies to receive relevant medical information. Patients also expressed an interest in having control over when and how they received this information, as well as being informed of how their data is used and shared with other researchers. Overall, the findings from this study suggest that there is scope to develop a digital platform to engage with patients so that they can receive

  10. Eosinophilic myositis as first manifestation in a patient with type 2 myotonic dystrophy CCTG expansion mutation and rheumatoid arthritis.

    PubMed

    Meyer, Alain; Lannes, Béatrice; Carapito, Raphaël; Bahram, Seiamak; Echaniz-Laguna, Andoni; Geny, Bernard; Sibilia, Jean; Gottenberg, Jacques Eric

    2015-02-01

    Eosinophilic myositis is characterized by eosinophilic infiltration of skeletal muscles. In the absence of an identifiable causative factor or source (including parasitic infection, intake of drugs or L-tryptophan, certain systemic disorders as well as malignant diseases), the diagnosis of idiopathic eosinophilic myositis is usually retained. However, some muscular dystrophies have been recently identified in this subset of eosinophilic myositis. Here, we report a patient with an 8 kb CCTG expansion in intron 1 of the CNBP gene, a mutation characteristic of myotonic dystrophy type 2 (DM2), whose first manifestation was "idiopathic" eosinophilic myositis. This report suggests that in "idiopathic" eosinophilic myositis, clinicians should consider muscular dystrophies, including DM2.

  11. Ovarian reserve and PGD treatment outcome in women with myotonic dystrophy.

    PubMed

    Srebnik, N; Margalioth, E J; Rabinowitz, R; Varshaver, I; Altarescu, G; Renbaum, P; Levi-Lahad, E; Weintraub, A; Eldar-Geva, T

    2014-07-01

    Myotonic dystrophy (DM) is the most common form of muscular dystrophy in adults. There are conflicting reports about its effect on female fertility. This study investigated ovarian reserve and IVF-preimplantation genetic diagnosis (PGD) outcome in women with DM1. A total of 21 women undergoing PGD for DM1 were compared with 21 age- and body mass index-matched women undergoing PGD for other diseases. Ovarian reserve markers, response to stimulation, embryo quality and clinical pregnancy and live birth rates were compared. Day-3 FSH concentration was higher, while anti-Müllerian hormone concentration and antral follicle count were lower in the DM1 group (median, range: 6.9 (1.8-11.3) versus 5.7 (1.5-10.7)IU/l; 0.9 (0.17-5.96) versus 2.68 (0.5-9.1)ng/ml; and 13 (0-63) versus 23 (8-40) follicles, respectively, all P < 0.05). Total FSH dose was higher (5200 versus 2250 IU, P = 0.004), while the numbers of oocytes retrieved (10 versus 16, P < 0.04) and metaphase-II oocytes (9 versus 12, P < 0.03) were lower in the DM1 group. The number of cycles with top-quality embryos and the clinical pregnancy rate were lower in the DM1 group. In conclusion, there is evidence of diminished ovarian reserve and less favourable IVF-PGD outcome in women with DM1. Myotonic Dystrophy (DM) is the most common form of muscular dystrophy in adults. There is evidence of subfertility in males affected with the disease but conflicting reports about the effect of the disease on female fertility. The aim of our study was to investigate ovarian reserve and IVF-PGD results in women with DM. Twenty-one women undergoing preimplantation genetic diagnosis (PGD) treatment for DM were compared to 21 age- and BMI matched women undergoing PGD treatment for other diseases. The two groups were compared for antral follicle count (AFC) and serum anti-Mullerian hormone (AMH) levels (the best known markers of ovarian reserve and fertility potential), ovarian response, embryo quality and pregnancy and live birth

  12. Body composition and clinical outcome measures in patients with myotonic dystrophy type 1.

    PubMed

    Sedehizadeh, Saam; Brook, J David; Maddison, Paul

    2017-03-01

    Myotonic Dystrophy type 1 (DM1) is the most common form of adult onset muscular dystrophy. In this study we compared body composition in DM1 and matched controls and evaluated the relationship between these parameters and clinical outcome measures in DM1 patients. In addition we established the sensitivity to change of these measures in a prospective 18 month longitudinal study of the DM1 patient cohort. Clinical data, manual muscle testing (MMT), quantitative muscle testing (QMT) of ankle dorsiflexion, bilateral grip dynamometry, 6 minute walk test and a DM1 functional rating scale (DM1-Activ) were collected at baseline (n = 38) and 18 month follow-up (n = 36). The case-control analysis was performed comparing baseline data with 31 anthropometrically matched controls. Dual-energy X-ray absorptiometry (DEXA) was used to obtain regional measurements of fat-free mass index (FFMI) and fat mass index (FMI) and demonstrated significant reduction of FFMI in the legs (left p = 0.004; right p = 0.017) and trunk (p < 0.0001) and increased FMI localised to the trunk (p < 0.0001) in DM1 patients compared to controls. Regional left and right arm FFMI and FMI significantly positively and negatively correlated with grip strength and both total FFMI (p = 0.0009) and FMI (p = 0.02) decreased and increased by 0.38 kg/m(2) and 0.31 kg/m(2) respectively after 18 month follow-up. DEXA is likely to provide a useful secondary outcome measurement of disease progression in addition to muscle strength and timed functional tasks in clinical trials.

  13. Abnormal functional brain connectivity and personality traits in myotonic dystrophy type 1.

    PubMed

    Serra, Laura; Silvestri, Gabriella; Petrucci, Antonio; Basile, Barbara; Masciullo, Marcella; Makovac, Elena; Torso, Mario; Spanò, Barbara; Mastropasqua, Chiara; Harrison, Neil A; Bianchi, Maria L E; Giacanelli, Manlio; Caltagirone, Carlo; Cercignani, Mara; Bozzali, Marco

    2014-05-01

    Myotonic dystrophy type 1 (DM1), the most common muscular dystrophy observed in adults, is a genetic multisystem disorder affecting several other organs besides skeletal muscle, including the brain. Cognitive and personality abnormalities have been reported; however, no studies have investigated brain functional networks and their relationship with personality traits/disorders in patients with DM1. To use resting-state functional magnetic resonance imaging to assess the potential relationship between personality traits/disorders and changes to functional connectivity within the default mode network (DMN) in patients with DM1. We enrolled 27 patients with genetically confirmed DM1 and 16 matched healthy control individuals. Patients underwent personality assessment using clinical interview and Minnesota Multiphasic Personality Inventory-2 administration; all participants underwent resting-state functional magnetic resonance imaging. Investigations were conducted at the Istituto di Ricovero e Cura a Carattere Scientifico Santa Lucia Foundation, Catholic University of Sacred Heart, and Azienda Ospedaliera San Camillo Forlanini. Resting-state functional magnetic resonance imaging. Measures of personality traits in patients and changes in functional connectivity within the DMN in patients and controls. Changes in functional connectivity and atypical personality traits in patients were correlated. We combined results obtained from the Minnesota Multiphasic Personality Inventory-2 and clinical interview to identify a continuum of atypical personality profiles ranging from schizotypal personality traits to paranoid personality disorder within our DM1 patients. We also demonstrated an increase in functional connectivity in the bilateral posterior cingulate and left parietal DMN nodes in DM1 patients compared with controls. Moreover, patients with DM1 showed strong associations between DMN functional connectivity and schizotypal-paranoid traits. Our findings provide novel

  14. Myotonic dystrophy type 2: human founder haplotype and evolutionary conservation of the repeat tract.

    PubMed

    Liquori, Christina L; Ikeda, Yoshio; Weatherspoon, Marcy; Ricker, Kenneth; Schoser, Benedikt G H; Dalton, Joline C; Day, John W; Ranum, Laura P W

    2003-10-01

    Myotonic dystrophy (DM), the most common form of muscular dystrophy in adults, can be caused by a mutation on either chromosome 19 (DM1) or 3 (DM2). In 2001, we demonstrated that DM2 is caused by a CCTG expansion in intron 1 of the zinc finger protein 9 (ZNF9) gene. To investigate the ancestral origins of the DM2 expansion, we compared haplotypes for 71 families with genetically confirmed DM2, using 19 short tandem repeat markers that we developed that flank the repeat tract. All of the families are white, with the majority of Northern European/German descent and a single family from Afghanistan. Several conserved haplotypes spanning >700 kb appear to converge into a single haplotype near the repeat tract. The common interval that is shared by all families with DM2 immediately flanks the repeat, extending up to 216 kb telomeric and 119 kb centromeric of the CCTG expansion. The DM2 repeat tract contains the complex repeat motif (TG)(n)(TCTG)(n)(CCTG)(n). The CCTG portion of the repeat tract is interrupted on normal alleles, but, as in other expansion disorders, these interruptions are lost on affected alleles. We examined haplotypes of 228 control chromosomes and identified a potential premutation allele with an uninterrupted (CCTG)(20) on a haplotype that was identical to the most common affected haplotype. Our data suggest that the predominant Northern European ancestry of families with DM2 resulted from a common founder and that the loss of interruptions within the CCTG portion of the repeat tract may predispose alleles to further expansion. To gain insight into possible function of the repeat tract, we looked for evolutionary conservation. The complex repeat motif and flanking sequences within intron 1 are conserved among human, chimpanzee, gorilla, mouse, and rat, suggesting a conserved biological function.

  15. Impairment of odor recognition and odor-induced emotions in type 1 myotonic dystrophy.

    PubMed

    Masaoka, Yuri; Kawamura, Mitsuru; Takeda, Akitoshi; Kobayakawa, Mutsutaka; Kuroda, Takeshi; Kasai, Hideyo; Tsuruya, Natsuko; Futamura, Akinori; Homma, Ikuo

    2011-10-10

    This study aimed to test whether type 1 myotonic dystrophy (DM1) patients who have a lower sensitivity to emotional facial expressions have an abnormal olfactory threshold or recognition level. We measured DM1 patients' performances in an olfactory acuity test and respiratory responses to odor stimuli, and compared their results to those of healthy controls (HCs). We found that DM1 patients exhibited a significantly reduced odor detection sensitivity compared with that in HCs. Three out of seven DM1 patients exhibited impaired odor recognition, while other four patients had significantly lower odor recognition compared with HCs. Even when patients were able to identify the type of odor, the levels of pleasantness they reported experiencing in response to a pleasant odor were significantly lower than those reported by HCs. These subjective data in DM1 patients were reflected in the respiratory responses (RRs). In the current study, one patient showed impairments in both odor detection and odor recognition. Abnormalities of the olfactory limbic areas might have been the cause of the olfactory impairments observed in the DM1 patients. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  16. Computerized hand grip myometry reliably measures myotonia and muscle strength in myotonic dystrophy (DM1).

    PubMed

    Moxley, Richard T; Logigian, Eric L; Martens, William B; Annis, Chris L; Pandya, Shree; Moxley, Richard T; Barbieri, Cheryl A; Dilek, Nuran; Wiegner, Allen W; Thornton, Charles A

    2007-09-01

    The aim of this study was to develop a reliable, sensitive, quantitative measure of grip myotonia and strength and to determine whether CTG repeat length is correlated with grip myotonia and with muscle strength in myotonic dystrophy type 1 (DM1). Three maximum voluntary isometric contractions (MVICs) of the finger flexors (i.e., handgrip) were recorded on 2 successive days using a computerized handgrip myometer in 29 genetically confirmed DM1 patients and 17 normals. An automated computer program calculated MVIC peak force (PF) and relaxation times (RTs) along the declining (relaxation) phase of the force recordings at 90%, 75%, 50%, 10%, and 5% of PF. Patients also underwent quantitative strength testing (QST) manual muscle testing (MMT). The patients had longer grip RTs and lower PFs than normals. RT (90% to 5%) was above the normal mean +2.5 SD in 25 (86%) patients. In DM1, prolongation of RT was mainly in the terminal (50% to 5%), rather than the initial (90% to 50%) phase of relaxation. PFs and RTs for each patient were reproducible on consecutive days. RTs were positively correlated with leukocyte CTG repeat length, whereas measures of muscle strength, such as PF, QST, and MMT, were negatively correlated with repeat length. We conclude that computerized handgrip myometry provides a sensitive, reliable measure of myotonia and strength in DM1 and offers a method to assess natural history and response to treatment.

  17. Atrial flutter in myotonic dystrophy type 1: Patient characteristics and clinical outcome.

    PubMed

    Wahbi, Karim; Sebag, Frederic A; Lellouche, Nicolas; Lazarus, Arnaud; Bécane, Henri-Marc; Bassez, Guillaume; Stojkovic, Tanya; Fayssoil, Abdallah; Laforêt, Pascal; Béhin, Anthony; Meune, Christophe; Eymard, Bruno; Duboc, Denis

    2016-03-01

    The prevalence and the incidence of atrial flutter in patients with myotonic dystrophy type 1 (DM1) and the most appropriate strategies for its management are unknown. We retrospectively included in the DM1 Heart Registry 929 adult patients with DM1 admitted to our Institutions between January 2000 and September 2013. We selected patients presenting with atrial flutter and analysed data relative to the occurrence of arterial thromboembolism, severe bradyarrhythmias and atrial flutter recurrences. Atrial flutter was present in 79 of the 929 patients included in our Registry, representing a 8.5% prevalence. Patients with atrial flutter were older, had a higher muscular disability rating scale score and had higher prevalence of other cardiac manifestations of DM1. Sixty patients presented with a first episode of atrial flutter, representing a 4.6% incidence. Severe bradyarrhythmias requiring permanent pacing were present in 4 patients (6.7%). Over a 53 ± 28 months mean follow-up duration, 2 patients (3.3%) had ischaemic stroke and 12 (20%) had atrial flutter recurrences. Patients who underwent radiofrequency ablation were more frequently free of atrial flutter recurrence than other patients (95 vs. 61%; HR = 0.17; P = 0.04). Atrial flutter is a common manifestation of DM1, potentially complicated by arterial thromboembolism or severe bradyarrhythmias. Radiofrequency catheter ablation is associated with a lower risk for recurrences. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Staufen1 impairs stress granule formation in skeletal muscle cells from myotonic dystrophy type 1 patients

    PubMed Central

    Ravel-Chapuis, Aymeric; Klein Gunnewiek, Amanda; Bélanger, Guy; Crawford Parks, Tara E.; Côté, Jocelyn; Jasmin, Bernard J.

    2016-01-01

    Myotonic dystrophy (DM1) is caused by an expansion of CUG repeats (CUGexp) in the DMPK mRNA 3′UTR. CUGexp-containing mRNAs become toxic to cells by misregulating RNA-binding proteins. Here we investigated the consequence of this RNA toxicity on the cellular stress response. We report that cell stress efficiently triggers formation of stress granules (SGs) in proliferating, quiescent, and differentiated muscle cells, as shown by the appearance of distinct cytoplasmic TIA-1– and DDX3-containing foci. We show that Staufen1 is also dynamically recruited into these granules. Moreover, we discovered that DM1 myoblasts fail to properly form SGs in response to arsenite. This blockage was not observed in DM1 fibroblasts, demonstrating a cell type–specific defect. DM1 myoblasts display increased expression and sequestration of toxic CUGexp mRNAs compared with fibroblasts. Of importance, down-regulation of Staufen1 in DM1 myoblasts rescues SG formation. Together our data show that Staufen1 participates in the inhibition of SG formation in DM1 myoblasts. These results reveal that DM1 muscle cells fail to properly respond to stress, thereby likely contributing to the complex pathogenesis of DM1. PMID:27030674

  19. Detection of linkage disequilibrium between the myotonic dystrophy locus and a new polymorphic DNA marker.

    PubMed Central

    Harley, H G; Brook, J D; Floyd, J; Rundle, S A; Crow, S; Walsh, K V; Thibault, M C; Harper, P S; Shaw, D J

    1991-01-01

    We have examined the linkage of two new polymorphic DNA markers (D19S62 and D19S63) and a previously unreported polymorphism with an existing DNA marker (ERCC1) to the myotonic dystrophy (DM) locus. In addition, we have used pulsed-field gel electrophoresis to obtain a fine-structure map of this region. The detection of linkage disequilibrium between DM and one of these markers (D19S63) is the first demonstration of this phenomenon in a heterogeneous DM population. The results suggest that at least 58% of DM patients in the British population, as well as those in a French-Canadian subpopulation, are descended from the same ancestral DM mutation. We discuss the implications of this finding in terms of strategies for cloning the DM gene, for a possible role in modification of risk for prenatal and presymptomatic testing, and we speculate on the origin and number of existing mutations which may result in a DM phenotype. PMID:2063878

  20. Targeting Toxic RNAs that Cause Myotonic Dystrophy Type 1 (DM1) with a Bisamidinium Inhibitor

    PubMed Central

    2015-01-01

    A working hypothesis for the pathogenesis of myotonic dystrophy type 1 (DM1) involves the aberrant sequestration of an alternative splicing regulator, MBNL1, by expanded CUG repeats, r(CUG)exp. It has been suggested that a reversal of the myotonia and potentially other symptoms of the DM1 disease can be achieved by inhibiting the toxic MBNL1-r(CUG)exp interaction. Using rational design, we discovered an RNA-groove binding inhibitor (ligand 3) that contains two triaminotriazine units connected by a bisamidinium linker. Ligand 3 binds r(CUG)12 with a low micromolar affinity (Kd = 8 ± 2 μM) and disrupts the MBNL1-r(CUG)12 interaction in vitro (Ki = 8 ± 2 μM). In addition, ligand 3 is cell and nucleus permeable, exhibits negligible toxicity to mammalian cells, dissolves MBNL1-r(CUG)exp ribonuclear foci, and restores misregulated splicing of IR and cTNT in a DM1 cell culture model. Importantly, suppression of r(CUG)exp RNA-induced toxicity in a DM1 Drosophila model was observed after treatment with ligand 3. These results suggest ligand 3 as a lead for the treatment of DM1. PMID:24702247

  1. Fertility in myotonic dystrophy in Saguenay-Lac-St-Jean: a historical perspective.

    PubMed

    Dao, T N; Mathieu, J; Bouchard, J P; De Braekeleer, M

    1992-11-01

    Myotonic dystrophy (MD) is an autosomal dominant disorder that has a high prevalence in Saguenay-Lac-St-Jean. A case-control study, based on a population register, of 373 MD patients who married in this region between 1855 and 1971 was conducted to determine whether their fertility was affected by the disorder. Six demographic parameters, that is the number of children, the age at marriage, the ages at the time of birth of the first and the last child, the interval between the marriage and the birth of the first child, and the interval between consecutive births, were analyzed. The mean number of children born to MD and control individuals was not different (P > 0.05). However, MD males had more children than MD females although they have started delaying their marriage since 1921. Fertility fell significantly in both the MD and control groups during the period of observation. This change reflects the decline in fertility of French Canadians in general during this period, but mainly after 1940.

  2. Segregation distortion of the CTG repeats at the myotonic dystrophy locus

    SciTech Connect

    Chakraborty, R.; Stivers, D.N.; Deka, R.; Yu, Ling M.; Shriver, M.D.; Ferrell, R.E.

    1996-07-01

    Myotonic dystrophy (DM), an autosomal dominant neuromuscular disease, is caused by a CTG-repeat expansion, with affected individuals having {ge}50 repeats of this trinucleotide, at the DMPK locus of human chromosome 19q13.3. Severely affected individuals die early in life; the milder form of this disease reduces reproductive ability. Alleles in the normal range of CTG repeats are not as unstable as the (CTG){sub {ge}50} alleles. In the DM families, anticipation and parental bias of allelic expansions have been noted. However, data on mechanism of maintenance of DM in populations are conflicting. We present a maximum-likelihood model for examining segregation distortion of CTG-repeat alleles in normal families. Analyzing 726 meiotic events in 95 nuclear families from the CEPH panel pedigrees, we find evidence of preferential transmission of larger alleles (of size {le}29 repeats) from females (the probability of transmission of larger alleles is .565 {plus_minus} 0.03, different from .5 at P {approx} .028). There is no evidence of segregation distortion during male meiosis. We propose a hypothesis that preferential transmission of larger CTG-repeat alleles during female meiosis can compensate for mutational contraction of repeats within the normal allelic size range, and reduced viability and fertility of affected individuals. Thus, the pool of premutant alleles at the DM locus can be maintained in populations, which can subsequently mutate to the full mutation status to give rise to DM. 31 refs., 1 fig., 5 tabs.

  3. Recruitment of human muscleblind proteins to (CUG)n expansions associated with myotonic dystrophy

    PubMed Central

    Miller, Jill W.; Urbinati, Carl R.; Teng-umnuay, Patana; Stenberg, Myrna G.; Byrne, Barry J.; Thornton, Charles A.; Swanson, Maurice S.

    2000-01-01

    Myotonic dystrophy (DM1) is an autosomal dominant neuromuscular disorder associated with a (CTG)n expansion in the 3′-untranslated region of the DM1 protein kinase (DMPK) gene. To explain disease pathogenesis, the RNA dominance model proposes that the DM1 mutation produces a gain-of-function at the RNA level in which CUG repeats form RNA hairpins that sequester nuclear factors required for proper muscle development and maintenance. Here, we identify the triplet repeat expansion (EXP) RNA-binding proteins as candidate sequestered factors. As predicted by the RNA dominance model, binding of the EXP proteins is specific for dsCUG RNAs and proportional to the size of the triplet repeat expansion. Remarkably, the EXP proteins are homologous to the Drosophila muscleblind proteins required for terminal differentiation of muscle and photoreceptor cells. EXP expression is also activated during mammalian myoblast differentiation, but the EXP proteins accumulate in nuclear foci in DM1 cells. We propose that DM1 disease is caused by aberrant recruitment of the EXP proteins to the DMPK transcript (CUG)n expansion. PMID:10970838

  4. Cognitive deficits and CTG repeat expansion size in classical myotonic dystrophy type 1 (DM1).

    PubMed

    Winblad, Stefan; Lindberg, Christopher; Hansen, Stefan

    2006-05-15

    This study was designed to investigate cognitive abilities and their correlations with CTG repeat expansion size in classical Myotonic dystrophy type 1 (DM1), given that earlier studies have indicated cognitive deficits, possibly correlating with blood CTG repeats expansion size. A measurement of CTG repeat expansion in lymphocytes and an extensive neuropsychological examination was made in 47 patients (25 women and 22 men). Individual results in the examination were compared with normative data. A substantial proportion of patients with DM1 (> 40%) scored worse in comparison to normative collectives on tests measuring executive, arithmetic, attention, speed and visuospatial abilities. We found significant correlations between longer CTG repeat expansion size and lower results on most tests associated with these abilities. Furthermore, the association between executive (frontal) deficits and DM1 were strengthened when considering both test results and correlations with CTG repeat expansion size in lymphocytes. This study showed deficits in several cognitive abilities when patients with DM1 are compared to normative collectives. Some of the neuropsychological tests associated with these abilities are correlated to CTG repeat expansion size in blood. These data highlight the importance of considering cognitive deficits when seeing patients with classical DM1 in clinical practice, but also the utility of using blood CTG repeat expansion size as a broad predictor of finding cognitive deficit in DM1.

  5. Role of Myotonic Dystrophy Protein Kinase (DMPK) in Glucose Homeostasis and Muscle Insulin Action

    PubMed Central

    Marti, Luc; Liesa, Marc; Camps, Marta; Ciaraldi, Theodore P.; Kondo, Richard; Reddy, Sita; Dillmann, Wolfgang H.; Palacin, Manuel; Zorzano, Antonio; Ruiz-Lozano, Pilar; Gomis, Ramon; Kaliman, Perla

    2007-01-01

    Myotonic dystrophy 1 (DM1) is caused by a CTG expansion in the 3′-unstranslated region of the DMPK gene, which encodes a serine/threonine protein kinase. One of the common clinical features of DM1 patients is insulin resistance, which has been associated with a pathogenic effect of the repeat expansions. Here we show that DMPK itself is a positive modulator of insulin action. DMPK-deficient (dmpk−/−) mice exhibit impaired insulin signaling in muscle tissues but not in adipocytes and liver, tissues in which DMPK is not expressed. Dmpk−/− mice display metabolic derangements such as abnormal glucose tolerance, reduced glucose uptake and impaired insulin-dependent GLUT4 trafficking in muscle. Using DMPK mutants, we show that DMPK is required for a correct intracellular trafficking of insulin and IGF-1 receptors, providing a mechanism to explain the molecular and metabolic phenotype of dmpk−/− mice. Taken together, these findings indicate that reduced DMPK expression may directly influence the onset of insulin-resistance in DM1 patients and point to dmpk as a new candidate gene for susceptibility to type 2-diabetes. PMID:17987120

  6. Electromechanical delays during a fatiguing exercise and recovery in patients with myotonic dystrophy type 1.

    PubMed

    Esposito, Fabio; Cè, Emiliano; Rampichini, Susanna; Monti, Elena; Limonta, Eloisa; Fossati, Barbara; Meola, Giovanni

    2017-03-01

    The partitioning of the electromechanical delay by an electromyographic (EMG), mechanomyographic (MMG) and force combined approach can provide further insight into the electrochemical and mechanical processes involved with skeletal muscle contraction and relaxation. The aim of the study was to monitor by this combined approach the changes in delays' electrochemical and mechanical components throughout a fatiguing task and during recovery in patients with myotonic dystrophy type 1 (DM1), who present at the skeletal muscle level fibres rearrangement, muscle weakness and myotonia, especially in the distal muscles. After assessing maximum voluntary contraction (MVC), 14 male patients with DM1 and 14 healthy controls (HC) performed a fatiguing exercise at 50% MVC until exhaustion. EMG, MMG, and force signals were recorded from tibialis anterior and vastus lateralis muscles. The electromechanical delay during contraction (DelayTOT) and relaxation (R-DelayTOT) components, EMG and MMG root mean square (RMS) and mean frequency (MF) were calculated off-line. The fatiguing exercise duration was similar in both groups. In patients with DM1, delays components were significantly longer compared to HC, especially in the distal muscle during relaxation. Delays components recovered quickly from the fatiguing exercise in HC than in patients with DM1 in both muscles. The alterations in delays observed in DM1 during the fatiguing exercise may indicate that also the lengthening of the electrochemical and mechanical processes during contraction and relaxation could play a role in explaining exercise intolerance in this pathology.

  7. How genetics affects the brain to produce higher-level dysfunctions in myotonic dystrophy type 1

    PubMed Central

    Serra, Laura; Petrucci, Antonio; Spanò, Barbara; Torso, Mario; Olivito, Giusy; Lispi, Ludovico; Costanzi-Porrini, Sandro; Giulietti, Giovanni; Koch, Giacomo; Giacanelli, Manlio; Caltagirone, Carlo; Cercignani, Mara; Bozzali, Marco

    2015-01-01

    Summary Myotonic dystrophy type 1 (DM1) is a multisystemic disorder dominated by muscular impairment and brain dysfunctions. Although brain damage has previously been demonstrated in DM1, its associations with the genetics and clinical/neuropsychological features of the disease are controversial. This study assessed the differential role of gray matter (GM) and white matter (WM) damage in determining higher-level dysfunctions in DM1. Ten patients with genetically confirmed DM1 and 16 healthy matched controls entered the study. The patients underwent a neuropsychological assessment and quantification of CTG triplet expansion. All the subjects underwent MR scanning at 3T, with studies including T1-weighted volumes and diffusion-weighted images. Voxel-based morphometry and tract-based spatial statistics were used for unbiased quantification of regional GM atrophy and WM integrity. The DM1 patients showed widespread involvement of both tissues. The extent of the damage correlated with CTG triplet expansion and cognition. This study supports the idea that genetic abnormalities in DM1 mainly target the WM, but GM involvement is also crucial in determining the clinical characteristics of DM1. PMID:26214024

  8. Patient-Reported Impact of Symptoms in Myotonic Dystrophy Type 2 (PRISM-2)

    PubMed Central

    Johnson, Nicholas; Bode, Rita; Dekdebrun, Jeanne; Dilek, Nuran; Hilbert, James E.; Luebbe, Elizabeth; Martens, William; McDermott, Michael P.; Quinn, Christine; Rothrock, Nan; Thornton, Charles; Vickrey, Barbara G.; Victorson, David; Moxley, Richard T.

    2015-01-01

    Objective: To determine the frequency and relative importance of the most life-affecting symptoms in myotonic dystrophy type 2 (DM2) and to identify the factors that have the strongest association with these symptoms. Methods: We conducted a cross-sectional study of adult patients with DM2 from a National Registry of DM2 Patients to assess the prevalence and relative importance of 310 symptoms and 21 symptomatic themes. Participant responses were compared by age categories, sex, educational attainment, employment status, and duration of symptoms. Results: The symptomatic themes with the highest prevalence in DM2 were the inability to do activities (94.4%), limitations with mobility or walking (89.2%), hip, thigh, or knee weakness (89.2%), fatigue (89.2%), and myotonia (82.6%). Participants identified the inability to do activities and fatigue as the symptomatic themes that have the greatest overall effect on their lives. Unemployment, a longer duration of symptoms, and less education were associated with a higher average prevalence of all symptomatic themes (p < 0.01). Unemployment, a longer duration of symptoms, sex, and increased age were associated with a higher average effect of all symptomatic themes among patients with DM2 (p < 0.01). Conclusions: The lives of patients with DM2 are affected by a variety of symptoms. These symptoms have different levels of significance and prevalence in this population and vary across DM2 subgroups in different demographic categories. PMID:26581301

  9. Electromechanical delay components during skeletal muscle contraction and relaxation in patients with myotonic dystrophy type 1.

    PubMed

    Esposito, Fabio; Cè, Emiliano; Rampichini, Susanna; Limonta, Eloisa; Venturelli, Massimo; Monti, Elena; Bet, Luciano; Fossati, Barbara; Meola, Giovanni

    2016-01-01

    The electromechanical delay during muscle contraction and relaxation can be partitioned into mainly electrochemical and mainly mechanical components by an EMG, mechanomyographic, and force combined approach. Component duration and measurement reliability were investigated during contraction and relaxation in a group of patients with myotonic dystrophy type 1 (DM1, n = 13) and in healthy controls (n = 13). EMG, mechanomyogram, and force were recorded in DM1 and in age- and body-matched controls from tibialis anterior (distal muscle) and vastus lateralis (proximal muscle) muscles during maximum voluntary and electrically-evoked isometric contractions. The electrochemical and mechanical components of the electromechanical delay during muscle contraction and relaxation were calculated off-line. Maximum strength was significantly lower in DM1 than in controls under both experimental conditions. All electrochemical and mechanical components were significantly longer in DM1 in both muscles. Measurement reliability was very high in both DM1 and controls. The high reliability of the measurements and the differences between DM1 patients and controls suggest that the EMG, mechanomyographic, and force combined approach could be utilized as a valid tool to assess the level of neuromuscular dysfunction in this pathology, and to follow the efficacy of pharmacological or non-pharmacological interventions.

  10. Reserved Sertoli cell function in the hypogonadic male patients with myotonic dystrophy.

    PubMed

    Lou, X Y; Nishi, Y; Haji, M; Antoku, Y; Tanaka, S; Ikuyama, S; Yanase, T; Takayanagi, R; Nawata, H

    1994-05-01

    To clarify the Sertoli cell and Leydig cell function in hypogonadic male patients with myotonic dystrophy (DM), serum concentrations of inhibin, total testosterone (TT), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were measured by radioimmunoassay in 6 male DM patients (41 to 56 years old, 47.7 +/- 5.05 years old) and compared with those in normal adult men. In 116 healthy men aged from 24 to 92 years, serum inhibin and TT levels decreased and serum FSH and LH concentrations increased with advancing age. There was an inverse correlation between serum inhibin and FSH. These results support the concept of negative feedback regulation system of FSH secretion by inhibin. Male DM patients showed significantly lower serum TT and higher concentrations of FSH and LH, compared with the age-matched 39 normal adult men (49-59 years old, 48.2 +/- 6.14 years old). However, there was no significant difference in serum inhibin levels between the patients and normal counterparts. These results indicate that the Sertoli cell function is reserved in male DM patient, although the Leydig cell function is impaired. It is also suggested that in these patients a negative feedback control system between inhibin and FSH may be disordered to some extent.

  11. Normal variation at the myotonic dystrophy locus in global human populations.

    PubMed Central

    Zerylnick, C; Torroni, A; Sherman, S L; Warren, S T

    1995-01-01

    Myotonic dystrophy (DM) is a dominant neuromuscular disease that results from an unstable CTG-repeat expansion in the 3' UTR of the myotonin kinase gene at 19q13.3. This repeat is normally polymorphic with a trimodal distribution reflecting 5-, 11-17-, and 19-30-repeat-length alleles. An absolute association between expanded CTG alleles and the 1-kb insertion allele of an intragenic polymorphism in Caucasians has led to the proposal that the 5-repeat allele gives rise to alleles of 19-30 repeats, from which expanded alleles are derived, a transition not involving the 11-17-repeat alleles. A survey of eight global populations confirms the stability of the 11-17-repeat alleles but shows disociation between the 1-kb insertion polymorphism and both the 5- and 19-30-repeat-length alleles. These data indicate more than one ancestral allele from which expanded alleles are derived and suggest that widely variable population frequencies of DM may reflect distinct frequencies of such predisposed alleles. Images Figure 2 Figure 3 Figure 4 PMID:7825567

  12. Foci of trinucleotide repeat transcripts in nuclei of myotonic dystrophy cells and tissues

    PubMed Central

    1995-01-01

    We have analyzed the intracellular localization of transcripts from the myotonin protein kinase (Mt-PK) gene in fibroblasts and muscle biopsies from myotonic dystrophy patients and normal controls. In affected individuals, a trinucleotide expansion in the gene results in the phenotype, the severity of which is proportional to the repeat length. A fluorochrome-conjugated probe (10 repeats of CAG) hybridized specifically to this expanded repeat. Mt-PK transcripts containing CTG repeat expansions were detected in the nucleus as bright foci in DM patient fibroblasts and muscle biopsies, but not from normal individuals. These foci represented transcripts from the Mt-PK gene since they simultaneously hybridized to fluorochrome-conjugated probes to the 5'-end of the Mt-PK mRNA. A single oligonucleotide probe to the repeat and the sense strand each conjugated to different fluorochromes revealed the gene and the transcripts simultaneously, and indicated that these focal concentrations (up to 13 per nucleus) represented predominately posttranscriptional RNA since only a single focus contained both the DNA and the RNA. This concentration of nuclear transcripts was diagnostic of the affected state, and may represent aberrant processing of the RNA. PMID:7896884

  13. MBNL Sequestration by Toxic RNAs and RNA Misprocessing in the Myotonic Dystrophy Brain.

    PubMed

    Goodwin, Marianne; Mohan, Apoorva; Batra, Ranjan; Lee, Kuang-Yung; Charizanis, Konstantinos; Fernández Gómez, Francisco José; Eddarkaoui, Sabiha; Sergeant, Nicolas; Buée, Luc; Kimura, Takashi; Clark, H Brent; Dalton, Joline; Takamura, Kenji; Weyn-Vanhentenryck, Sebastien M; Zhang, Chaolin; Reid, Tammy; Ranum, Laura P W; Day, John W; Swanson, Maurice S

    2015-08-18

    For some neurological disorders, disease is primarily RNA mediated due to expression of non-coding microsatellite expansion RNAs (RNA(exp)). Toxicity is thought to result from enhanced binding of proteins to these expansions and depletion from their normal cellular targets. However, experimental evidence for this sequestration model is lacking. Here, we use HITS-CLIP and pre-mRNA processing analysis of human control versus myotonic dystrophy (DM) brains to provide compelling evidence for this RNA toxicity model. MBNL2 binds directly to DM repeat expansions in the brain, resulting in depletion from its normal RNA targets with downstream effects on alternative splicing and polyadenylation. Similar RNA processing defects were detected in Mbnl compound-knockout mice, highlighted by dysregulation of Mapt splicing and fetal tau isoform expression in adults. These results demonstrate that MBNL proteins are directly sequestered by RNA(exp) in the DM brain and introduce a powerful experimental tool to evaluate RNA-mediated toxicity in other expansion diseases. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  14. Cognitive deficits and CTG repeat expansion size in classical myotonic dystrophy type 1 (DM1)

    PubMed Central

    Winblad, Stefan; Lindberg, Christopher; Hansen, Stefan

    2006-01-01

    Background This study was designed to investigate cognitive abilities and their correlations with CTG repeat expansion size in classical Myotonic dystrophy type 1 (DM1), given that earlier studies have indicated cognitive deficits, possibly correlating with blood CTG repeats expansion size. Methods A measurement of CTG repeat expansion in lymphocytes and an extensive neuropsychological examination was made in 47 patients (25 women and 22 men). Individual results in the examination were compared with normative data. Results A substantial proportion of patients with DM1 (> 40%) scored worse in comparison to normative collectives on tests measuring executive, arithmetic, attention, speed and visuospatial abilities. We found significant correlations between longer CTG repeat expansion size and lower results on most tests associated with these abilities. Furthermore, the association between executive (frontal) deficits and DM1 were strengthened when considering both test results and correlations with CTG repeat expansion size in lymphocytes. Conclusion This study showed deficits in several cognitive abilities when patients with DM1 are compared to normative collectives. Some of the neuropsychological tests associated with these abilities are correlated to CTG repeat expansion size in blood. These data highlight the importance of considering cognitive deficits when seeing patients with classical DM1 in clinical practice, but also the utility of using blood CTG repeat expansion size as a broad predictor of finding cognitive deficit in DM1. PMID:16696870

  15. Health supervision and anticipatory guidance in adult myotonic dystrophy type 1.

    PubMed

    Gagnon, C; Chouinard, M C; Laberge, L; Veillette, S; Bégin, P; Breton, R; Jean, S; Brisson, D; Gaudet, D; Mathieu, J

    2010-12-01

    The complexity and variability of disease manifestations in myotonic dystrophy (DM1) pose a challenge for the clinical management of patients. The follow-up of DM1 patients has been described as fragmented, inadequate or even deficient for many patients. Through a systematic review of the medical and social literature and a validation process with a DM1 expert panel, we summarized systemic and social concerns clinically relevant to DM1 and revisited recommendations for treatment. This article summarizes common manifestations of the central nervous system, visual, respiratory, cardiac, gastro-intestinal, genito-urinary, muscular and metabolic impairments. In addition, we emphasized the social features of DM1 such as low education attainment, low employment, poor familial and social environment and poor social participation. While cardiac, respiratory and swallowing problems affect life expectancy, it is often excessive daytime sleepiness, fatigue, gastro-intestinal and cognitive behavioural manifestations that are the most disabling features of the disorder. A more holistic approach in the management of DM1 and a purposeful integrated organization of care involving all members of the patients' environment including family, clinicians, decision-makers and community organizations are needed to move out of the spiral of disease and handicap and move toward optimal citizenship and quality of life.

  16. Small Molecules that Target the Toxic RNA in Myotonic Dystrophy Type 2

    PubMed Central

    Nguyen, Lien; Lee, JuYeon

    2014-01-01

    Myotonic dystrophy type 2 is caused by an expansion of CCTG repeats in the zinc-finger protein gene (ZNF9). Transcribed CCUG repeats sequester MBNL1, an important alternative splicing regulator, preventing its normal function, leading to the disease phenotype. We describe a series of ligands that disrupt the MBNL1-r(CCUG)n interaction as potential lead agents for developing DM2 therapeutics. A previously reported triaminopyrimidine-acridine conjugate was a moderate inhibitor in vitro, however it proved to be poorly water-soluble and not cell-permeable. To improve its therapeutic potential, the new set of ligands maintained the key triaminopyrimidine recognition unit but replaced the acridine intercalator with a bisamidinium groove binder. The optimized ligands exhibit low micromolar inhibition potency to MBNL1-r(CCUG)8. Importantly, the ligands are the first to show the ability to disrupt the MBNL1-r(CCUG)n foci in DM2 model cell culture and exhibit low cellular cytotoxicity. PMID:24938413

  17. Rational Design of Bioactive, Modularly Assembled Aminoglycosides Targeting the RNA that Causes Myotonic Dystrophy Type 1

    PubMed Central

    Childs-Disney, Jessica L.; Parkesh, Raman; Nakamori, Masayuki; Thornton, Charles A.; Disney, Matthew D.

    2012-01-01

    Myotonic dystrophy type 1 (DM1) is caused when an expanded r(CUG) repeat (r(CUG)exp) binds the RNA splicing regulator muscleblind-like 1 protein (MBNL1) as well as other proteins. Previously, we reported that modularly assembled small molecules displaying a 6′-N-5-hexynoate kanamycin A RNA-binding module (K) on a peptoid backbone potently inhibit the binding of MBNL1 to r(CUG)exp. However, these parent compounds are not appreciably active in cell-based models of DM1. The lack of potency was traced to suboptimal cellular permeability and localization. To improve these properties, second-generation compounds that are conjugated to a D-Arg9 molecular transporter were synthesized. These modified compounds enter cells in higher concentrations than the parent compounds and are efficacious in cell-based DM1 model systems at low micromolar concentrations. In particular, they improve three defects that are the hallmarks of DM1: a translational defect due to nuclear retention of transcripts containing r(CUG)exp; pre-mRNA splicing defects due to inactivation of MBNL1; and the formation of nuclear foci. The best compound in cell-based studies was tested in a mouse model of DM1. Modest improvement of pre-mRNA splicing defects was observed. These studies suggest that a modular assembly approach can afford bioactive compounds that target RNA. PMID:23130637

  18. Structure of the Myotonic Dystrophy Type 2 RNA and Designed Small Molecules That Reduce Toxicity

    PubMed Central

    Park, HaJeung; Lohman, Jeremy R.; Guan, Lirui; Tran, Tuan; Sarkar, Partha; Schatz, George C.; Disney, Matthew D.

    2014-01-01

    Myotonic dystrophy type 2 (DM2) is an untreatable neuromuscular disorder caused by a r(CCUG) expansion (r(CCUG)exp) that folds into an extended hairpin with periodically repeating 2×2 nucleotide internal loops (5’CCUG/3’GUCC). We designed multivalent compounds that improve DM2-associated defects using information about RNA-small molecule interactions. We also report the first crystal structure of r(CCUG)exp refined to 2.35 Å. Structural analysis of the three 5’CCUG/3’GUCC repeat internal loops (L) reveals that the CU pairs in L1 are each stabilized by one hydrogen bond and a water-mediated hydrogen bond while CU pairs in L2 and L3 are stabilized by two hydrogen bonds. Molecular dynamics (MD) simulations reveal that the CU pairs are dynamic and stabilized by Na+ and water molecules. MD simulations of the binding of the small molecule to r(CCUG) repeats reveal that the lowest free energy binding mode occurs via the major groove, in which one C residue is unstacked and the cross-strand nucleotides are displaced. Moreover, we modeled the binding of our dimeric compound to two 5’CCUG/3’GUCC motifs, which shows that the scaffold on which the RNA-binding modules are displayed provides an optimal distance to span two adjacent loops. PMID:24341895

  19. Rationally designed small molecules that target both the DNA and RNA causing myotonic dystrophy type 1.

    PubMed

    Nguyen, Lien; Luu, Long M; Peng, Shaohong; Serrano, Julio F; Chan, H Y Edwin; Zimmerman, Steven C

    2015-11-11

    Single-agent, single-target therapeutic approaches are often limited by a complex disease pathobiology. We report rationally designed, multi-target agents for myotonic dystrophy type 1 (DM1). DM1 originates in an abnormal expansion of CTG repeats (CTG(exp)) in the DMPK gene. The resultant expanded CUG transcript (CUG(exp)) identified as a toxic agent sequesters important proteins, such as muscleblind-like proteins (MBNL), undergoes repeat-associated non-ATG (RAN) translation, and potentially causes microRNA dysregulation. We report rationally designed small molecules that target the DM1 pathobiology in vitro in three distinct ways by acting simultaneously as transcription inhibitors, by inhibiting aberrant protein binding to the toxic RNA, and by acting as RNase mimics to degrade the toxic RNA. In vitro, the agents are shown to (1) bind CTG(exp) and inhibit formation of the CUG(exp) transcript, (2) bind CUG(exp) and inhibit sequestration of MBNL1, and (3) cleave CUG(exp) in an RNase-like manner. The most potent compounds are capable of reducing the levels of CUG(exp) in DM1 model cells, and one reverses two separate CUG(exp)-induced phenotypes in a DM1 Drosophila model.

  20. Derepressing muscleblind expression by miRNA sponges ameliorates myotonic dystrophy-like phenotypes in Drosophila

    PubMed Central

    Cerro-Herreros, Estefania; Fernandez-Costa, Juan M.; Sabater-Arcis, María; Llamusi, Beatriz; Artero, Ruben

    2016-01-01

    Myotonic Dystrophy type 1 (DM1) originates from alleles of the DMPK gene with hundreds of extra CTG repeats in the 3′ untranslated region (3′ UTR). CUG repeat RNAs accumulate in foci that sequester Muscleblind-like (MBNL) proteins away from their functional target transcripts. Endogenous upregulation of MBNL proteins is, thus, a potential therapeutic approach to DM1. Here we identify two miRNAs, dme-miR-277 and dme-miR-304, that differentially regulate muscleblind RNA isoforms in miRNA sensor constructs. We also show that their sequestration by sponge constructs derepresses endogenous muscleblind not only in a wild type background but also in a DM1 Drosophila model expressing non-coding CUG trinucleotide repeats throughout the musculature. Enhanced muscleblind expression resulted in significant rescue of pathological phenotypes, including reversal of several mis-splicing events and reduced muscle atrophy in DM1 adult flies. Rescued flies had improved muscle function in climbing and flight assays, and had longer lifespan compared to disease controls. These studies provide proof of concept for a similar potentially therapeutic approach to DM1 in humans. PMID:27805016

  1. Small molecule kinase inhibitors alleviate different molecular features of myotonic dystrophy type 1.

    PubMed

    Wojciechowska, Marzena; Taylor, Katarzyna; Sobczak, Krzysztof; Napierala, Marek; Krzyzosiak, Wlodzimierz J

    2014-01-01

    Expandable (CTG)n repeats in the 3' UTR of the DMPK gene are a cause of myotonic dystrophy type 1 (DM1), which leads to a toxic RNA gain-of-function disease. Mutant RNAs with expanded CUG repeats are retained in the nucleus and aggregate in discrete inclusions. These foci sequester splicing factors of the MBNL family and trigger upregulation of the CUGBP family of proteins resulting in the mis-splicing of their target transcripts. To date, many efforts to develop novel therapeutic strategies have been focused on disrupting the toxic nuclear foci and correcting aberrant alternative splicing via targeting mutant CUG repeats RNA; however, no effective treatment for DM1 is currently available. Herein, we present results of culturing of human DM1 myoblasts and fibroblasts with two small-molecule ATP-binding site-specific kinase inhibitors, C16 and C51, which resulted in the alleviation of the dominant-negative effects of CUG repeat expansion. Reversal of the DM1 molecular phenotype includes a reduction of the size and number of foci containing expanded CUG repeat transcripts, decreased steady-state levels of CUGBP1 protein, and consequent improvement of the aberrant alternative splicing of several pre-mRNAs misregulated in DM1.

  2. Increased autophagy and apoptosis contribute to muscle atrophy in a myotonic dystrophy type 1 Drosophila model.

    PubMed

    Bargiela, Ariadna; Cerro-Herreros, Estefanía; Fernandez-Costa, Juan M; Vilchez, Juan J; Llamusi, Beatriz; Artero, Ruben

    2015-07-01

    Muscle mass wasting is one of the most debilitating symptoms of myotonic dystrophy type 1 (DM1) disease, ultimately leading to immobility, respiratory defects, dysarthria, dysphagia and death in advanced stages of the disease. In order to study the molecular mechanisms leading to the degenerative loss of adult muscle tissue in DM1, we generated an inducible Drosophila model of expanded CTG trinucleotide repeat toxicity that resembles an adult-onset form of the disease. Heat-shock induced expression of 480 CUG repeats in adult flies resulted in a reduction in the area of the indirect flight muscles. In these model flies, reduction of muscle area was concomitant with increased apoptosis and autophagy. Inhibition of apoptosis or autophagy mediated by the overexpression of DIAP1, mTOR (also known as Tor) or muscleblind, or by RNA interference (RNAi)-mediated silencing of autophagy regulatory genes, achieved a rescue of the muscle-loss phenotype. In fact, mTOR overexpression rescued muscle size to a size comparable to that in control flies. These results were validated in skeletal muscle biopsies from DM1 patients in which we found downregulated autophagy and apoptosis repressor genes, and also in DM1 myoblasts where we found increased autophagy. These findings provide new insights into the signaling pathways involved in DM1 disease pathogenesis.

  3. Validation of plasma microRNAs as biomarkers for myotonic dystrophy type 1

    PubMed Central

    Perfetti, A.; Greco, S.; Cardani, R.; Fossati, B.; Cuomo, G.; Valaperta, R.; Ambrogi, F.; Cortese, A.; Botta, A.; Mignarri, A.; Santoro, M.; Gaetano, C.; Costa, E.; Dotti, M. T.; Silvestri, G.; Massa, R.; Meola, G.; Martelli, F.

    2016-01-01

    Non-invasive and simple to measure biomarkers are still an unmet need for myotonic dystrophy type 1 (DM1). Indeed, muscle biopsies can be extremely informative, but their invasive nature limits their application. Extracellular microRNAs are emerging humoral biomarkers and preliminary studies identified a group of miRNAs that are deregulated in the plasma or serum of small groups of DM1 patients. Here we adopted very stringent selection and normalization criteria to validate or disprove these miRNAs in 103 DM1 patients and 111 matched controls. We confirmed that 8 miRNAs out of 12 were significantly deregulated in DM1 patients: miR-1, miR-27b, miR-133a, miR-133b, miR-206, miR-140-3p, miR-454 and miR-574. The levels of these miRNAs, alone or in combination, discriminated DM1 from controls significantly, and correlated with both skeletal muscle strength and creatine kinase values. Interestingly, miR-133b levels were significantly higher in DM1 female patients. Finally, the identified miRNAs were also deregulated in the plasma of a small group (n = 30) of DM2 patients. In conclusion, this study proposes that miRNAs might be useful as DM1 humoral biomarkers. PMID:27905532

  4. Swallowing assessment in myotonic dystrophy type 1 using fiberoptic endoscopic evaluation of swallowing (FEES).

    PubMed

    Pilz, Walmari; Baijens, Laura W J; Passos, Valéria Lima; Verdonschot, Rob; Wesseling, Frederik; Roodenburg, Nel; Faber, Catharina G; Kremer, Bernd

    2014-12-01

    This study describes the swallowing function of patients with myotonic dystrophy type 1 (DM1) and the effect of bolus consistency on swallowing in this group. The aim of the study is twofold: (a) to identify which (and to what extent) swallowing variables change for DM1 patients relative to healthy control subjects and (b) to examine whether the degree of oropharyngeal dysphagia is associated with disease severity. Forty-five consecutive DM1 patients and ten healthy subjects underwent a swallowing assessment, at Maastricht University medical Center in the Netherlands. The assessment included a standardized fiberoptic endoscopic evaluation of swallowing (FEES) protocol using different bolus consistencies. Clinical severity of the disease was assessed using the muscular impairment rating scale (MIRS). Significant differences were found between patients and controls for all FEES variables. The magnitude of these differences depended on the bolus consistency. The odds of a more pathological swallowing outcome increased significantly with higher MIRS levels. In conclusion, swallowing function is found to be significantly altered in DM1 patients. The results emphasize the importance of conducting a detailed swallowing assessment in all patients, even those with mild muscle weakness.

  5. Short antisense-locked nucleic acids (all-LNAs) correct alternative splicing abnormalities in myotonic dystrophy.

    PubMed

    Wojtkowiak-Szlachcic, Agnieszka; Taylor, Katarzyna; Stepniak-Konieczna, Ewa; Sznajder, Lukasz J; Mykowska, Agnieszka; Sroka, Joanna; Thornton, Charles A; Sobczak, Krzysztof

    2015-03-31

    Myotonic dystrophy type 1 (DM1) is an autosomal dominant multisystemic disorder caused by expansion of CTG triplet repeats in 3'-untranslated region of DMPK gene. The pathomechanism of DM1 is driven by accumulation of toxic transcripts containing expanded CUG repeats (CUG(exp)) in nuclear foci which sequester several factors regulating RNA metabolism, such as Muscleblind-like proteins (MBNLs). In this work, we utilized very short chemically modified antisense oligonucleotides composed exclusively of locked nucleic acids (all-LNAs) complementary to CUG repeats, as potential therapeutic agents against DM1. Our in vitro data demonstrated that very short, 8- or 10-unit all-LNAs effectively bound the CUG repeat RNA and prevented the formation of CUG(exp)/MBNL complexes. In proliferating DM1 cells as well as in skeletal muscles of DM1 mouse model the all-LNAs induced the reduction of the number and size of CUG(exp) foci and corrected MBNL-sensitive alternative splicing defects with high efficacy and specificity. The all-LNAs had low impact on the cellular level of CUG(exp)-containing transcripts and did not affect the expression of other transcripts with short CUG repeats. Our data strongly indicate that short all-LNAs complementary to CUG repeats are a promising therapeutic tool against DM1.

  6. Supine changes in lung function correlate with chronic respiratory failure in myotonic dystrophy patients.

    PubMed

    Poussel, Mathias; Kaminsky, Pierre; Renaud, Pierre; Laroppe, Julien; Pruna, Lelia; Chenuel, Bruno

    2014-03-01

    Quality of life and prognosis of patients with myotonic dystrophy type 1 (MD1) often depend on the degree of lung function impairment. This study was designed to assess the respective prevalence of ventilatory restriction, hypoxaemia and hypercapnia in MD1 patients and to determine whether postural changes in lung function could contribute to the early diagnosis of poor respiratory outcome. Fifty-eight patients (42.6±12.9 years) with MD1 were prospectively evaluated from April 2008 to June 2010 to determine their supine and upright lung function and arterial blood gases. The prevalence of ventilatory restriction was 36% and increased with the severity of muscular disability (from 7.7% to 70.6%). The prevalence of hypoxaemia and hypercapnia was 37.9% and 25.9%, respectively. Multiple regression analysis showed that the supine fall in FEV1 was the only variable associated with ventilatory restriction, hypoxaemia and hypercapnia. Our data indicate that supine evaluation of lung function could be helpful to predict poor respiratory outcome, which is closely correlated with hypoxaemia and/or hypercapnia.

  7. Characteristic MRI Findings of upper Limb Muscle Involvement in Myotonic Dystrophy Type 1.

    PubMed

    Sugie, Kazuma; Sugie, Miho; Taoka, Toshio; Tonomura, Yasuyo; Kumazawa, Aya; Izumi, Tesseki; Kichikawa, Kimihiko; Ueno, Satoshi

    2015-01-01

    The objective of our study was to evaluate the relation between muscle MRI findings and upper limb weakness with grip myotonia in patients with myotonic dystrophy type 1 (DM1). Seventeen patients with DM1 were evaluated by manual muscle strength testing and muscle MRI of the upper limbs. Many DM1 patients presenting with decreased grasping power frequently showed high intensity signals in the flexor digitorum profundus (FDP) muscles on T1-weighted imaging. Patients presenting with upper limb weakness frequently also showed high intensity signals in the flexor pollicis longus, abductor pollicis longus, and extensor pollicis muscles. Disturbances of the distal muscles of the upper limbs were predominant in all DM1 patients. Some DM1 patients with a prolonged disease duration showed involvement of not only distal muscles but also proximal muscles in the upper limbs. Muscle involvement of the upper limbs on MRI strongly correlated positively with the disease duration or the numbers of CTG repeats. To our knowledge, this is the first study to provide a detailed description of the distribution and severity of affected muscles of the upper limbs on MRI in patients with DM1. We conclude that muscle MRI findings are very useful for identifying affected muscles and predicting the risk of muscle weakness in the upper limbs of DM1 patients.

  8. Abnormal splicing switch of DMD's penultimate exon compromises muscle fibre maintenance in myotonic dystrophy

    PubMed Central

    Rau, Frédérique; Lainé, Jeanne; Ramanoudjame, Laetitita; Ferry, Arnaud; Arandel, Ludovic; Delalande, Olivier; Jollet, Arnaud; Dingli, Florent; Lee, Kuang-Yung; Peccate, Cécile; Lorain, Stéphanie; Kabashi, Edor; Athanasopoulos, Takis; Koo, Taeyoung; Loew, Damarys; Swanson, Maurice S.; Le Rumeur, Elisabeth; Dickson, George; Allamand, Valérie; Marie, Joëlle; Furling, Denis

    2015-01-01

    Myotonic Dystrophy type 1 (DM1) is a dominant neuromuscular disease caused by nuclear-retained RNAs containing expanded CUG repeats. These toxic RNAs alter the activities of RNA splicing factors resulting in alternative splicing misregulation and muscular dysfunction. Here we show that the abnormal splicing of DMD exon 78 found in dystrophic muscles of DM1 patients is due to the functional loss of MBNL1 and leads to the re-expression of an embryonic dystrophin in place of the adult isoform. Forced expression of embryonic dystrophin in zebrafish using an exon-skipping approach severely impairs the mobility and muscle architecture. Moreover, reproducing Dmd exon 78 missplicing switch in mice induces muscle fibre remodelling and ultrastructural abnormalities including ringed fibres, sarcoplasmic masses or Z-band disorganization, which are characteristic features of dystrophic DM1 skeletal muscles. Thus, we propose that splicing misregulation of DMD exon 78 compromises muscle fibre maintenance and contributes to the progressive dystrophic process in DM1. PMID:26018658

  9. Rational design of bioactive, modularly assembled aminoglycosides targeting the RNA that causes myotonic dystrophy type 1.

    PubMed

    Childs-Disney, Jessica L; Parkesh, Raman; Nakamori, Masayuki; Thornton, Charles A; Disney, Matthew D

    2012-12-21

    Myotonic dystrophy type 1 (DM1) is caused when an expanded r(CUG) repeat (r(CUG)(exp)) binds the RNA splicing regulator muscleblind-like 1 protein (MBNL1) as well as other proteins. Previously, we reported that modularly assembled small molecules displaying a 6'-N-5-hexynoate kanamycin A RNA-binding module (K) on a peptoid backbone potently inhibit the binding of MBNL1 to r(CUG)(exp). However, these parent compounds are not appreciably active in cell-based models of DM1. The lack of potency was traced to suboptimal cellular permeability and localization. To improve these properties, second-generation compounds that are conjugated to a d-Arg(9) molecular transporter were synthesized. These modified compounds enter cells in higher concentrations than the parent compounds and are efficacious in cell-based DM1 model systems at low micromolar concentrations. In particular, they improve three defects that are the hallmarks of DM1: a translational defect due to nuclear retention of transcripts containing r(CUG)(exp); pre-mRNA splicing defects due to inactivation of MBNL1; and the formation of nuclear foci. The best compound in cell-based studies was tested in a mouse model of DM1. Modest improvement of pre-mRNA splicing defects was observed. These studies suggest that a modular assembly approach can afford bioactive compounds that target RNA.

  10. Structure of the myotonic dystrophy type 2 RNA and designed small molecules that reduce toxicity.

    PubMed

    Childs-Disney, Jessica L; Yildirim, Ilyas; Park, HaJeung; Lohman, Jeremy R; Guan, Lirui; Tran, Tuan; Sarkar, Partha; Schatz, George C; Disney, Matthew D

    2014-02-21

    Myotonic dystrophy type 2 (DM2) is an incurable neuromuscular disorder caused by a r(CCUG) expansion (r(CCUG)(exp)) that folds into an extended hairpin with periodically repeating 2×2 nucleotide internal loops (5'CCUG/3'GUCC). We designed multivalent compounds that improve DM2-associated defects using information about RNA-small molecule interactions. We also report the first crystal structure of r(CCUG) repeats refined to 2.35 Å. Structural analysis of the three 5'CCUG/3'GUCC repeat internal loops (L) reveals that the CU pairs in L1 are each stabilized by one hydrogen bond and a water-mediated hydrogen bond, while CU pairs in L2 and L3 are stabilized by two hydrogen bonds. Molecular dynamics (MD) simulations reveal that the CU pairs are dynamic and stabilized by Na(+) and water molecules. MD simulations of the binding of the small molecule to r(CCUG) repeats reveal that the lowest free energy binding mode occurs via the major groove, in which one C residue is unstacked and the cross-strand nucleotides are displaced. Moreover, we modeled the binding of our dimeric compound to two 5'CCUG/3'GUCC motifs, which shows that the scaffold on which the RNA-binding modules are displayed provides an optimal distance to span two adjacent loops.

  11. Clusters of cognitive impairment among different phenotypes of myotonic dystrophy type 1 and type 2.

    PubMed

    Peric, Stojan; Rakocevic Stojanovic, Vidosava; Mandic Stojmenovic, Gorana; Ilic, Vera; Kovacevic, Masa; Parojcic, Aleksandra; Pesovic, Jovan; Mijajlovic, Milija; Savic-Pavicevic, Dusanka; Meola, Giovanni

    2017-03-01

    Neuropsychological examinations in myotonic dystrophy (DM) patients show a great variability of results from a condition of intellectual disability to the subtle cognitive impairments. It is unclear if different clusters of neuropsychological deficits appear in different phenotypes of DM, or if there are patients with no cognitive deficit at all. The aim of this study is to assess cognitive impairments among patients with different phenotypes of DM type 1 (DM1) and type 2 (DM2), and to potentially define cognitive clusters in these disorders. Study comprised 101 DM1 and 46 DM2 adult patients who were genetically confirmed. Patients underwent analysis of five cognitive domains (visuospatial, executive, attention, memory and language). Virtually all DM1 patients had cognitive defect with approximately 2-3 cognitive domains affected. On the other hand, one-third of DM2 patients had completely normal neuropsychological findings, and in other two-thirds approximately 1-2 domains were affected. Cluster analysis showed that in both diseases visuospatial and executive dysfunctions seemed to be the main cognitive defects, while memory and language impairments appeared in more severe phenotypes. Our results showed that a single form of DM1 or DM2 may consist of several cognitive clusters. Understanding of cognitive impairments in DM is very important to follow positive and side effects in ongoing and future clinical trials.

  12. Fatigue and daytime sleepiness rating scales in myotonic dystrophy: a study of reliability

    PubMed Central

    Laberge, L; Gagnon, C; Jean, S; Mathieu, J

    2005-01-01

    Objectives: To assess the reliability of the Epworth Sleepiness Scale (ESS), Daytime Sleepiness Scale (DSS), Chalder Fatigue Scale (CFS), and Krupp's Fatigue Severity Scale (KFSS) in patients with myotonic dystrophy type 1 (DM1). Methods: In total, 27 patients with DM1 were administered the questionnaires on two occasions, with a 2 week interval. Internal consistency and test retest reliability were measured using intraclass correlation coefficients (ICCs), and Cronbach's α, Cohen's κ, and Goodman-Kruskal's γ coefficients. Results: Internal consistency of the CFS and KFSS were adequate (α>0.70) but that of the ESS was weak (α = 0.24). Both daytime sleepiness and fatigue rating scales showed significant test retest reliability. Test retest reliability for individual items revealed inconsistencies for some ESS and CFS items. Conclusions: Reliability of the CFS, DSS, and KFSS was high, allowing their use for individual patients with DM1, but that of the ESS was lower, rendering its current usage in DM1 questionable. Fatigue rating scales such as the KFSS, which are based on the behavioural consequences of fatigue, may constitute a more accurate and comprehensive measure of fatigue severity in the DM1 population. PMID:16170085

  13. [Case of myotonic dystrophy with pulmonary atelectasis and torsade de pointes in the perioperative period].

    PubMed

    Shibata, Junpei; Fujisawa, Tatsuro; Shimizu, Sari; Ide, Soichiro; Kumasaka, Mikiko; Sugiyama, Daisuke; Hishinuma, Miwako; Kitoh, Takeshi

    2008-10-01

    A 42-year-old woman with myotonic dystrophy (MD) was scheduled for total hysterectomy and left ovariectomy. The patient received intravenous induction of anesthesia with propofol 60 mg and vecuronium 4 mg. Anesthesia was maintained with a minimum dose of propofol, air, oxygen and epidural anesthesia with the catheter at the T12-L1 level. Surgery and anesthesia were uneventful except for transient decreased Sp(O2) during anesthesia induction due to a septum in the left main bronchus. Chest radiographs at the end of surgery showed atelectasis of the whole left lung. Therefore, the patient was kept intubated, sedated with propofol, and mechanically ventilated in the intensive care unit. During the course of its treatment, torsade de pointes (TdP) ventricular tachycardia suddenly occurred but resolved spontaneously within 45 sec. without any medications. Prolonged QT interval by hypokalemia was suspected as the main factor. With the patient of MD, we have to pay attention to weakening of reserve capacity of pulmonary function and lethal arrhythmia in the perioperative period.

  14. Brain Connectomics' Modification to Clarify Motor and Nonmotor Features of Myotonic Dystrophy Type 1

    PubMed Central

    Serra, Laura; Mancini, Matteo; Silvestri, Gabriella; Petrucci, Antonio; Masciullo, Marcella; Spanò, Barbara; Torso, Mario; Mastropasqua, Chiara; Giacanelli, Manlio; Caltagirone, Carlo; Cercignani, Mara; Meola, Giovanni; Bozzali, Marco

    2016-01-01

    The adult form of myotonic dystrophy type 1 (DM1) presents with paradoxical inconsistencies between severity of brain damage, relative preservation of cognition, and failure in everyday life. This study, based on the assessment of brain connectivity and mechanisms of plasticity, aimed at reconciling these conflicting issues. Resting-state functional MRI and graph theoretical methods of analysis were used to assess brain topological features in a large cohort of patients with DM1. Patients, compared to controls, revealed reduced connectivity in a large frontoparietal network that correlated with their isolated impairment in visuospatial reasoning. Despite a global preservation of the topological properties, peculiar patterns of frontal disconnection and increased parietal-cerebellar connectivity were also identified in patients' brains. The balance between loss of connectivity and compensatory mechanisms in different brain networks might explain the paradoxical mismatch between structural brain damage and minimal cognitive deficits observed in these patients. This study provides a comprehensive assessment of brain abnormalities that fit well with both motor and nonmotor clinical features experienced by patients in their everyday life. The current findings suggest that measures of functional connectivity may offer the possibility of characterizing individual patients with the potential to become a clinical tool. PMID:27313901

  15. Ultrasound-enhanced delivery of Morpholino with Bubble liposomes ameliorates the myotonia of myotonic dystrophy model mice

    PubMed Central

    Koebis, Michinori; Kiyatake, Tamami; Yamaura, Hiroshi; Nagano, Kanako; Higashihara, Mana; Sonoo, Masahiro; Hayashi, Yukiko; Negishi, Yoichi; Endo-Takahashi, Yoko; Yanagihara, Dai; Matsuda, Ryoichi; Takahashi, Masanori P.; Nishino, Ichizo; Ishiura, Shoichi

    2013-01-01

    Phosphorodiamidate morpholino oligonucleotide (PMO)-mediated control of the alternative splicing of the chloride channel 1 (CLCN1) gene is a promising treatment for myotonic dystrophy type 1 (DM1) because the abnormal splicing of this gene causes myotonia in patients with DM1. In this study, we optimised a PMO sequence to correct Clcn1 alternative splicing and successfully remedied the myotonic phenotype of a DM1 mouse model, the HSALR mouse. To enhance the efficiency of delivery of PMO into HSALR mouse muscles, Bubble liposomes, which have been used as a gene delivery tool, were applied with ultrasound exposure. Effective delivery of PMO led to increased expression of Clcn1 protein in skeletal muscle and the amelioration of myotonia. Thus, PMO-mediated control of the alternative splicing of the Clcn1 gene must be important target of antisense therapy of DM1. PMID:23873129

  16. Excessive daytime sleepiness in a patient with coexisting myotonic dystrophy type 1, myasthenia gravis and Graves' disease.

    PubMed

    Kapica-Topczewska, Katarzyna; Pogorzelski, Robert; Tarasiuk, Joanna; Drozdowski, Wiesław; Lewczuk, Piotr; Kułakowska, Alina

    A 41-year-old female with history of Graves' disease, bilateral cataract, paroxysmal atrial fibrillation was admitted because of muscle weakness, daytime sleepiness, fatigability, drowsiness, bilateral eyelid ptosis, descending of head and lower jaw. On neurological examination the patient was presented with muscle weakness, muscle atrophy (in face and sternocleidomastoid muscles), features of myotonia and apocamnosis (orbicular muscles). Electromyography revealed myopathic changes, myotonic and pseudomyotonic discharges, positive repetitive nerve stimulation test in proximal muscles. Myotonic dystrophy (MD) diagnosis was confirmed by genetic testing and myasthenia gravis (MG) by a positive titer of cholinergic receptor autoantibodies. In the CSF concentration of hypocretin was significantly decreased. Copyright © 2017 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  17. Expression profiling of muscles from Fukuyama-type congenital muscular dystrophy and laminin-alpha 2 deficient congenital muscular dystrophy; is congenital muscular dystrophy a primary fibrotic disease?

    PubMed

    Taniguchi, Mariko; Kurahashi, Hiroki; Noguchi, Satoru; Sese, Jun; Okinaga, Takeshi; Tsukahara, Toshifumi; Guicheney, Pascale; Ozono, Keiichi; Nishino, Ichizo; Morishita, Shinichi; Toda, Tatsushi

    2006-04-07

    Fukuyama-type congenital muscular dystrophy (FCMD) and laminin-alpha2 deficient congenital muscular dystrophy (MDC1A) are congenital muscular dystrophies (CMDs) and they both are categorized into the same clinical entity of muscular dystrophy as Duchenne muscular dystrophy (DMD). All three disorders share a common etiologic defect in the dystrophin-glycoprotein complex, which connects muscle structural proteins with the extracellular basement membrane. To investigate the pathophysiology of these CMDs, we generated microarray gene expression profiles of skeletal muscle from patients in various clinical stages. Despite diverse pathological changes, the correlation coefficient of overall gene expression among these samples was considerably high. We performed a multi-dimensional statistical analysis, the Distillation, to extract determinant genes that distinguish CMD muscle from normal controls. Up-regulated genes were primarily extracellular matrix (ECM) components, whereas down-regulated genes included structural components of mature muscle. These observations reflect active interstitial fibrosis with less active regeneration of muscle cell components in the CMDs, characteristics that are clearly distinct from those of DMD. Although the severity of fibrosis varied among the specimens tested, ECM gene expression was consistently high without substantial changes through the clinical course. Further, in situ hybridization showed more prominent ECM gene expression on muscle cells than on interstitial tissue cells, suggesting that ECM components are induced by regeneration process rather than by 'dystrophy.' These data imply that the etiology of FCMD and MDC1A differs from that of the chronic phase of classical muscular dystrophy, and the major pathophysiologic change in CMDs might instead result from primary active fibrosis.

  18. Myotonic dystrophy type 1 and de novo FSHD mutation double trouble: a clinical and muscle MRI study.

    PubMed

    Masciullo, M; Iannaccone, E; Bianchi, M L E; Santoro, M; Conte, G; Modoni, A; Monforte, M; Tasca, G; Laschena, F; Ricci, E; Silvestri, G

    2013-05-01

    Here we describe the first case of myotonic dystrophy type 1 (DM1) associated with facio-scapulo-humeral dystrophy (FSHD). From a clinical point of view, the patient displayed a pattern of muscle involvement reminiscent of both disorders, including hand-grip myotonia, facial, axial and distal limbs muscle weakness as well as a bilateral winged scapula associated with atrophy of the pectoralis major muscle and lumbar lordosis; pelvic muscles were mostly spared. An extensive muscle MRI assessment including neck, shoulder, abdominal, pelvic and lower limb muscles documented radiological features typical of DM1 and FSDH. Molecular genetic studies confirmed that the proband carried both a pathologically expanded DMPK allele, inherited from his father, and a de novo shortened D4Z4 repeat fragment at 4q35 locus.

  19. Muscleblind, BSF and TBPH are mislocalized in the muscle sarcomere of a Drosophila myotonic dystrophy model

    PubMed Central

    Llamusi, Beatriz; Bargiela, Ariadna; Fernandez-Costa, Juan M.; Garcia-Lopez, Amparo; Klima, Raffaella; Feiguin, Fabian; Artero, Ruben

    2013-01-01

    SUMMARY Myotonic dystrophy type 1 (DM1) is a genetic disease caused by the pathological expansion of a CTG trinucleotide repeat in the 3′ UTR of the DMPK gene. In the DMPK transcripts, the CUG expansions sequester RNA-binding proteins into nuclear foci, including transcription factors and alternative splicing regulators such as MBNL1. MBNL1 sequestration has been associated with key features of DM1. However, the basis behind a number of molecular and histological alterations in DM1 remain unclear. To help identify new pathogenic components of the disease, we carried out a genetic screen using a Drosophila model of DM1 that expresses 480 interrupted CTG repeats, i(CTG)480, and a collection of 1215 transgenic RNA interference (RNAi) fly lines. Of the 34 modifiers identified, two RNA-binding proteins, TBPH (homolog of human TAR DNA-binding protein 43 or TDP-43) and BSF (Bicoid stability factor; homolog of human LRPPRC), were of particular interest. These factors modified i(CTG)480 phenotypes in the fly eye and wing, and TBPH silencing also suppressed CTG-induced defects in the flight muscles. In Drosophila flight muscle, TBPH, BSF and the fly ortholog of MBNL1, Muscleblind (Mbl), were detected in sarcomeric bands. Expression of i(CTG)480 resulted in changes in the sarcomeric patterns of these proteins, which could be restored by coexpression with human MBNL1. Epistasis studies showed that Mbl silencing was sufficient to induce a subcellular redistribution of TBPH and BSF proteins in the muscle, which mimicked the effect of i(CTG)480 expression. These results provide the first description of TBPH and BSF as targets of Mbl-mediated CTG toxicity, and they suggest an important role of these proteins in DM1 muscle pathology. PMID:23118342

  20. Pentamidine rescues contractility and rhythmicity in a Drosophila model of myotonic dystrophy heart dysfunction

    PubMed Central

    Chakraborty, Mouli; Selma-Soriano, Estela; Magny, Emile; Couso, Juan Pablo; Pérez-Alonso, Manuel; Charlet-Berguerand, Nicolas; Artero, Ruben; Llamusi, Beatriz

    2015-01-01

    ABSTRACT Up to 80% of individuals with myotonic dystrophy type 1 (DM1) will develop cardiac abnormalities at some point during the progression of their disease, the most common of which is heart blockage of varying degrees. Such blockage is characterized by conduction defects and supraventricular and ventricular tachycardia, and carries a high risk of sudden cardiac death. Despite its importance, very few animal model studies have focused on the heart dysfunction in DM1. Here, we describe the characterization of the heart phenotype in a Drosophila model expressing pure expanded CUG repeats under the control of the cardiomyocyte-specific driver GMH5-Gal4. Morphologically, expression of 250 CUG repeats caused abnormalities in the parallel alignment of the spiral myofibrils in dissected fly hearts, as revealed by phalloidin staining. Moreover, combined immunofluorescence and in situ hybridization of Muscleblind and CUG repeats, respectively, confirmed detectable ribonuclear foci and Muscleblind sequestration, characteristic features of DM1, exclusively in flies expressing the expanded CTG repeats. Similarly to what has been reported in humans with DM1, heart-specific expression of toxic RNA resulted in reduced survival, increased arrhythmia, altered diastolic and systolic function, reduced heart tube diameters and reduced contractility in the model flies. As a proof of concept that the fly heart model can be used for in vivo testing of promising therapeutic compounds, we fed flies with pentamidine, a compound previously described to improve DM1 phenotypes. Pentamidine not only released Muscleblind from the CUG RNA repeats and reduced ribonuclear formation in the Drosophila heart, but also rescued heart arrhythmicity and contractility, and improved fly survival in animals expressing 250 CUG repeats. PMID:26515653

  1. Identification of Plant-derived Alkaloids with Therapeutic Potential for Myotonic Dystrophy Type I.

    PubMed

    Herrendorff, Ruben; Faleschini, Maria Teresa; Stiefvater, Adeline; Erne, Beat; Wiktorowicz, Tatiana; Kern, Frances; Hamburger, Matthias; Potterat, Olivier; Kinter, Jochen; Sinnreich, Michael

    2016-08-12

    Myotonic dystrophy type I (DM1) is a disabling neuromuscular disease with no causal treatment available. This disease is caused by expanded CTG trinucleotide repeats in the 3' UTR of the dystrophia myotonica protein kinase gene. On the RNA level, expanded (CUG)n repeats form hairpin structures that sequester splicing factors such as muscleblind-like 1 (MBNL1). Lack of available MBNL1 leads to misregulated alternative splicing of many target pre-mRNAs, leading to the multisystemic symptoms in DM1. Many studies aiming to identify small molecules that target the (CUG)n-MBNL1 complex focused on synthetic molecules. In an effort to identify new small molecules that liberate sequestered MBNL1 from (CUG)n RNA, we focused specifically on small molecules of natural origin. Natural products remain an important source for drugs and play a significant role in providing novel leads and pharmacophores for medicinal chemistry. In a new DM1 mechanism-based biochemical assay, we screened a collection of isolated natural compounds and a library of over 2100 extracts from plants and fungal strains. HPLC-based activity profiling in combination with spectroscopic methods were used to identify the active principles in the extracts. The bioactivity of the identified compounds was investigated in a human cell model and in a mouse model of DM1. We identified several alkaloids, including the β-carboline harmine and the isoquinoline berberine, that ameliorated certain aspects of the DM1 pathology in these models. Alkaloids as a compound class may have potential for drug discovery in other RNA-mediated diseases. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. The 1.5-Mb region spanning the myotonic dystrophy locus shows uniform recombination frequency.

    PubMed

    Shutler, G G; MacKenzie, A E; Korneluk, R G

    1994-01-01

    The myotonic dystrophy (DM) mutation has been identified as a heritable unstable CTG trinucleotide repeat sequence. The intergenerational amplification of this sequence is an example of a new class of dynamic mutations responsible for human genetic diseases. To ascertain whether recombination activity influences, or is affected by, the presence of this unique sequence, a comprehensive study of the physical and genetic mapping data for the 1.5-Mb region of human chromosome 19q13.3, which contains the DM locus, was conducted. The recombination rate for this region was examined by correlating genetic distance to physical distance for six selected marker loci. The following markers span the DM region: 19qCEN-p alpha 1.4 (D19S37)-APOC2-CKM-pE0.8 (D19S115)-pGB2.6 (DM)-p134c (D19S51)-19qTER. Initial linear regression analysis of these two parameters failed to reveal a significant linear correlation (coefficient of determination, r2 = .19), suggesting nonuniform rates of recombination. However, the presence of a recombination hot spot was believed to be unlikely, as the marker-to-marker pairs that showed the greatest deviation in recombination frequency were not restricted to a specific region of the 1.5 Mb studied and had relatively broad confidence intervals, as reflected by low LOD values. A second linear regression analysis using only marker intervals with high LOD scores (Zmax > 22) showed linear correlation (r2 = .68) for the entire 1.5-Mb region. This analysis indicated a relatively uniform recombination frequency in the 1.5-Mb region spanning the DM locus. Furthermore, the recombinations observed were neither under- nor overrepresented on DM chromosomes. Consequently, recombination activity is unlikely to influence, or be affected by, the presence of the DM mutation.

  3. Usefulness of clinical and electrocardiographic data for predicting adverse cardiac events in patients with myotonic dystrophy

    PubMed Central

    Breton, Robert; Mathieu, Jean

    2009-01-01

    BACKGROUND: Myotonic dystrophy type 1 (DM1) has been associated with an increased risk of sudden death, either by heart block or malignant ventricular arrhythmias. Identifying patients at risk remains difficult and no consensus has been reached regarding the best approach for follow-up and prevention of sudden death. OBJECTIVES: To identify noninvasive clinical and electrocardiographic predictors of adverse cardiac events in patients with DM1. METHODS: Clinical and serial electrocardiographic data on 428 patients with a DNA-proven diagnosis of DM1, followed during a mean period of 11.7 years, were reviewed. Variables associated with adverse cardiac events were identified. RESULTS: Eleven patients (2.6%) experienced sudden death and 13 (3.0%) required implantation of a pacemaker. On univariate analysis, adverse events were associated with advancing age, prolongation of the PR, QRS and corrected QT (QTc) intervals, as well as the degree of neuromuscular impairment. No such relationship was found with the extent of genetic anomaly (number of cytosine-thymine-guanine repeats). However, multivariate analysis using Cox proportional hazards models showed that only baseline PR and QTc intervals were significantly linked to the end points of sudden death or pacemaker implantation; the age-adjusted RR was 3.7 (95% CI 1.5 to 8.6) if baseline PR was 200 ms or longer (P=0.003), and 3.0 (95% CI 1.0 to 8.8) if the baseline QTc was 450 ms or longer (P=0.047). CONCLUSIONS: In a large unselected cohort of 428 patients with DM1, the cumulative incidence of sudden death was relatively low, and the delayed conduction on surface electrocardiogram was found to be potentially helpful for identifying patients at risk for sudden death or pacemaker implantation. PMID:19214296

  4. Frontostriatal dysexecutive syndrome: a core cognitive feature of myotonic dystrophy type 2.

    PubMed

    Peric, Stojan; Mandic-Stojmenovic, Gorana; Stefanova, Elka; Savic-Pavicevic, Dusanka; Pesovic, Jovan; Ilic, Vera; Dobricic, Valerija; Basta, Ivana; Lavrnic, Dragana; Rakocevic-Stojanovic, Vidosava

    2015-01-01

    The aim of this study was to assess cognitive status in a large group of patients with myotonic dystrophy type 2 (DM2) compared to type 1 (DM1) subjects matched for gender and age, using a comprehensive battery of neuropsychological tests. Thirty-four genetically confirmed adult DM2 patients were recruited and matched for gender and age with 34 adult-onset DM1 subjects. All patients underwent detailed classic pen and pencil neuropsychological investigation and also computerized automated battery-CANTAB. More than half of DM2 patients had abnormal results on executive tests [Intra/Extradimensional Set Shift (IED), Stockings of Cambridge (SOC)] and verbal episodic memory (Ray Auditory Verbal Learning Test). Regarding DM1, abnormal results in more than 50 % of subjects were achieved in even ten tests, including visuospatial, language, executive, cognitive screening and visual memory tests. Direct comparison between patient groups showed that lower percentage of DM2 patients had abnormal results on following tests: Addenbrooke's Cognitive Examination-Revised, Raven Standard Progressive Matrices, Block Design, copy and recall of Rey-Osterieth Complex Figure, number of categories and perseverative responses on Wisconsin Card Sorting Test and Boston Naming Test (p < 0.01), as well as Trail Making Test-B and Spatial Span (p < 0.05). Our results showed significant dysexecutive syndrome and certain impairment of episodic verbal memory in DM2 patients that are reflective of frontal (especially frontostriatal) and temporal lobe dysfunction. On the other hand, dysexecutive and visuospatial/visuoconstructional deficits predominate in DM1 which correspond to the frontal, parietal (and occipital) lobe dysfunction.

  5. Micro-RNA expression in muscle and fiber morphometry in myotonic dystrophy type 1.

    PubMed

    Fritegotto, Chiara; Ferrati, Chiara; Pegoraro, Valentina; Angelini, Corrado

    2017-04-01

    We aimed to explore the cellular action of micro-RNAs that are non-coding-RNAs modulating gene expression, whose expression is dysregulated in myotonic dystrophy (DM1). Basic procedure was to measure the levels of muscle-specific myo-miRNAs (miR-1, miR-133a/b, miR-206) in muscle of 12 DM1 patients. Muscle fiber morphometry and a new grading of histopathological severity score were used to compare specific myo-miRNA level and fiber atrophy. We found that the levels of miR-1 and miR-133a/b were significantly decreased, while miR-206 was significantly increased as compared to controls. The histopathological score did not significantly correlate with the levels of myo-miRNAs, even if the lowest levels of miRNA-1 and miRNA-133a/b, and the highest levels of miRNA-206 were observed in patients with either severe histopathological scores or long disease duration. The histopathological score was inversely correlated with disease duration. Nowadays that DM1 muscle biopsies are scanty, since patients are usually diagnosed by genetic analysis, our study offers a unique opportunity to present miRNA expression profiles in muscle and correlate them to muscle morphology in this rare multisystem disorder. Our molecular and morphologic data suggest a post-transcriptional regulatory action of myo-miRNA in DM1, highlighting their potential role as biomarkers of muscle plasticity.

  6. Pentamidine rescues contractility and rhythmicity in a Drosophila model of myotonic dystrophy heart dysfunction.

    PubMed

    Chakraborty, Mouli; Selma-Soriano, Estela; Magny, Emile; Couso, Juan Pablo; Pérez-Alonso, Manuel; Charlet-Berguerand, Nicolas; Artero, Ruben; Llamusi, Beatriz

    2015-12-01

    Up to 80% of individuals with myotonic dystrophy type 1 (DM1) will develop cardiac abnormalities at some point during the progression of their disease, the most common of which is heart blockage of varying degrees. Such blockage is characterized by conduction defects and supraventricular and ventricular tachycardia, and carries a high risk of sudden cardiac death. Despite its importance, very few animal model studies have focused on the heart dysfunction in DM1. Here, we describe the characterization of the heart phenotype in a Drosophila model expressing pure expanded CUG repeats under the control of the cardiomyocyte-specific driver GMH5-Gal4. Morphologically, expression of 250 CUG repeats caused abnormalities in the parallel alignment of the spiral myofibrils in dissected fly hearts, as revealed by phalloidin staining. Moreover, combined immunofluorescence and in situ hybridization of Muscleblind and CUG repeats, respectively, confirmed detectable ribonuclear foci and Muscleblind sequestration, characteristic features of DM1, exclusively in flies expressing the expanded CTG repeats. Similarly to what has been reported in humans with DM1, heart-specific expression of toxic RNA resulted in reduced survival, increased arrhythmia, altered diastolic and systolic function, reduced heart tube diameters and reduced contractility in the model flies. As a proof of concept that the fly heart model can be used for in vivo testing of promising therapeutic compounds, we fed flies with pentamidine, a compound previously described to improve DM1 phenotypes. Pentamidine not only released Muscleblind from the CUG RNA repeats and reduced ribonuclear formation in the Drosophila heart, but also rescued heart arrhythmicity and contractility, and improved fly survival in animals expressing 250 CUG repeats.

  7. Association of peripheral neuropathy with sleep-related breathing disorders in myotonic dystrophies

    PubMed Central

    Banach, Marta; Antczak, Jakub; Rola, Rafał

    2017-01-01

    Background Myotonic dystrophy (DM) type 1 and type 2 are inherited diseases characterized by myotonia and myopathy. Additional symptoms include, among others, peripheral neuropathy and sleep-related breathing disorders (SRBDs). There is growing evidence for a complex association between DM1 and DM2, which was described in patients with diabetes mellitus and in the general population. In this study, we investigated whether there is an association between peripheral neuropathy and SRBDs also in the population of patients with DM. Methods The study included 16 patients with DM1 (mean age, 37.9±14.1 years; 20–69 years) and eight patients with DM2 (mean age, 47.6±14.1 years; 20–65 years), who underwent a sensory and motor nerve conduction study (NCS) and diagnostic screening for SRBDs. In both groups, the NCS parameters were correlated with respiratory parameters. Results In both groups, the amplitude of the ulnar sensory nerve action potential (SNAP) correlated with the mean arterial oxygen saturation (SaO2). In addition, in the DM2 group, the median SNAP correlated with the mean SaO2. In the DM1 group, the median SNAP and the distal motor latency (DML) of the ulnar nerve correlated with the apnea–hypopnea index, while the oxygen desaturation index correlated with the DML of the tibial nerve and with conduction velocity in the sural nerve. Conclusion Our results indicate a complex association between neuropathy and SRBDs in DM1 and DM2. Axonal degeneration may contribute to nocturnal hypoxemia and vice versa. Neuropathy may contribute to muscle weakness, which in turn may cause respiratory events. PMID:28138246

  8. Characteristics of Intergenerational Contractions of the CTG Repeat in Myotonic Dystrophy

    PubMed Central

    Ashizawa, T.; Anvret, M.; Baiget, M.; Barceló, J. M.; Brunner, H.; Cobo, A. M.; Dallapiccola, B.; Fenwick, R. G.; Grandell, U.; Harley, H.; Junien, C.; Koch, M. C.; Korneluk, R. G.; Lavedan, C.; Miki, T.; Mulley, J. C.; de Munain, A. López; Novelli, G.; Roses, A. D.; Seltzer, W. K.; Shaw, D. J.; Smeets, H.; Sutherland, G. R.; Yamagata, H.; Harper, P. S.

    1994-01-01

    In myotonic dystrophy (DM), the size of a CTG repeat in the DM kinase gene generally increases in successive generations with clinical evidence of anticipation. However, there have also been cases with an intergenerational contraction of the repeat. We examined 1,489 DM parent-offspring pairs, of which 95 (6.4%) showed such contractions in peripheral blood leukocytes (PBL). In 56 of the 95 pairs, clinical data allowed an analysis of their anticipation status. It is surprising that anticipation occurred in 27 (48%) of these 56 pairs, while none clearly showed a later onset of DM in the symptomatic offspring. The contraction occurred in 76 (10%) of 753 paternal transmissions and in 19 (3%) of 736 maternal transmissions. Anticipation was observed more frequently in maternal (85%) than in paternal (37%) transmissions (P < .001). The parental repeat size correlated with the size of intergenerational contraction (r2 = .50, P « .001), and the slope of linear regression was steeper in paternal (–.62) than in maternal (–.30) transmissions (P « .001). Sixteen DM parents had multiple DM offspring with the CTG repeat contractions. This frequency was higher than the frequency expected from the probability of the repeat contractions (6.4%) and the size of DM sib population (1.54 DM offspring per DM parent, in 968 DM parents). We conclude that (1) intergenerational contraction of the CTG repeat in leukocyte DNA frequently accompanies apparent anticipation, especially when DM is maternally transmitted, and (2) the paternal origin of the repeat and the presence of the repeat contraction in a sibling increase the probability of the CTG repeat contraction. PMID:8116611

  9. Relation of cardiac abnormalities and CTG-repeat size in myotonic dystrophy.

    PubMed

    Finsterer, J; Gharehbaghi-Schnell, E; Stöllberger, C; Fheodoroff, K; Seiser, A

    2001-05-01

    It is unclear if the severity of cardiac involvement in patients with myotonic dystrophy (MD) is related to the size of the CTG-repeat expansion. This open, uncontrolled, observational, prospective study aimed to find out if there is a relation between the severity of cardiac involvement in MD and the CTG-repeat size. In 21 patients with MD, (8 women, 13 men, aged 11-88 years) a detailed cardiologic examination, including history, clinical examination, electrocardiography (ECG), transthoracic echocardiography and ambulatory 24-h ECG, was carried out and cardiac involvement was assessed according to a previously described scoring system. Additionally, the CTG-repeat size was determined from nuclear DNA of blood leukocytes. The correlation between the CTG-repeat size and the mean heart rate, PQ-interval, QTc-interval, fractional shortening, left ventricular enddiastolic diameter, septal thickness, posterior wall thickness, mean heart rate on 24-h ECG and cardiac involvement score was r=0.47, r=0.086, r=0.11, r=-0.27, r=-0.34, r=-0.06, r=-0.12, r=0.16 and r=0.09 (all p>0.05), respectively. In patients 21-30, 31-40 and 41-50 years of age, cardiac involvement increased with increasing CTG-repeat size. In younger patients, the number of CTG-repeats needed to develop a reasonable cardiac involvement was higher than in older patients. Depending on age, cardiac involvement increases with increasing CTG-repeat size obtained from blood leukocytes in patients with MD.

  10. Noninvasive assessment of respiratory muscle strength and activity in Myotonic dystrophy

    PubMed Central

    Evangelista, Morgana de Araújo; Dias, Fernando Augusto Lavezzo; Dourado Júnior, Mário Emílio Teixeira; do Nascimento, George Carlos; Gualdi, Lucien Peroni; Aliverti, Andrea; Resqueti, Vanessa; Fregonezi, Guilherme Augusto de Freitas

    2017-01-01

    Objective To evaluate sensitivity/specificity of the maximum relaxation rate (MRR) of inspiratory muscles, amplitude of electromyographic activity of the sternocleidomastoid (SCM), scalene (SCA), parasternal (2ndIS) and rectus abdominis (RA) muscles; lung function and respiratory muscle strength in subjects with Myotonic dystrophy type 1 (DM1) compared with healthy subjects. Design and methods Quasi-experimental observational study with control group. MRR of inspiratory muscles, lung function and amplitude of the electromyographic activity of SCM, SCA, 2ndIS and RA muscles during maximum inspiratory pressure (PImax), maximum expiratory pressure (PEmax) and sniff nasal inspiratory pressure (SNIP) tests were assessed in eighteen DM1 subjects and eleven healthy. Results MRR was lower in DM1 group compared to healthy (P = 0.001) and was considered sensitive and specific to identify disease in DM1 and discard it in controls, as well as SNIP% (P = 0.0026), PImax% (P = 0.0077) and PEmax% (P = 0.0002). Contraction time of SCM and SCA was higher in DM1 compared to controls, respectively, during PImax (P = 0.023 and P = 0.017) and SNIP (P = 0.015 and P = .0004). The DM1 group showed lower PImax (P = .0006), PEmax (P = 0.0002), SNIP (P = 0.0014), and higher electromyographic activity of the SCM (P = 0.002) and SCA (P = 0.004) at rest; of 2ndIS (P = 0.003) during PEmax and of SCM (P = 0.02) and SCA (P = 0.03) during SNIP test. Conclusions MD1 subjects presented restrictive pattern, reduced respiratory muscle strength, muscular electrical activity and MRR when compared to higher compared to controls. In addition, the lower MRR found in MD1 subjects showed to be reliable to sensitivity and specificity in identifying the delayed relaxation of respiratory muscles. PMID:28594857

  11. Noninvasive assessment of respiratory muscle strength and activity in Myotonic dystrophy.

    PubMed

    Evangelista, Morgana de Araújo; Dias, Fernando Augusto Lavezzo; Dourado Júnior, Mário Emílio Teixeira; do Nascimento, George Carlos; Sarmento, Antonio; Gualdi, Lucien Peroni; Aliverti, Andrea; Resqueti, Vanessa; Fregonezi, Guilherme Augusto de Freitas

    2017-01-01

    To evaluate sensitivity/specificity of the maximum relaxation rate (MRR) of inspiratory muscles, amplitude of electromyographic activity of the sternocleidomastoid (SCM), scalene (SCA), parasternal (2ndIS) and rectus abdominis (RA) muscles; lung function and respiratory muscle strength in subjects with Myotonic dystrophy type 1 (DM1) compared with healthy subjects. Quasi-experimental observational study with control group. MRR of inspiratory muscles, lung function and amplitude of the electromyographic activity of SCM, SCA, 2ndIS and RA muscles during maximum inspiratory pressure (PImax), maximum expiratory pressure (PEmax) and sniff nasal inspiratory pressure (SNIP) tests were assessed in eighteen DM1 subjects and eleven healthy. MRR was lower in DM1 group compared to healthy (P = 0.001) and was considered sensitive and specific to identify disease in DM1 and discard it in controls, as well as SNIP% (P = 0.0026), PImax% (P = 0.0077) and PEmax% (P = 0.0002). Contraction time of SCM and SCA was higher in DM1 compared to controls, respectively, during PImax (P = 0.023 and P = 0.017) and SNIP (P = 0.015 and P = .0004). The DM1 group showed lower PImax (P = .0006), PEmax (P = 0.0002), SNIP (P = 0.0014), and higher electromyographic activity of the SCM (P = 0.002) and SCA (P = 0.004) at rest; of 2ndIS (P = 0.003) during PEmax and of SCM (P = 0.02) and SCA (P = 0.03) during SNIP test. MD1 subjects presented restrictive pattern, reduced respiratory muscle strength, muscular electrical activity and MRR when compared to higher compared to controls. In addition, the lower MRR found in MD1 subjects showed to be reliable to sensitivity and specificity in identifying the delayed relaxation of respiratory muscles.

  12. Daytime sleepiness and REM sleep characteristics in myotonic dystrophy: a case-control study.

    PubMed

    Yu, Huan; Laberge, Luc; Jaussent, Isabelle; Bayard, Sophie; Scholtz, Sabine; Raoul, Morales; Pages, Michel; Dauvilliers, Yves

    2011-02-01

    Excessive daytime sleepiness (EDS) and high daytime REM sleep pressure are important sleep features of myotonic dystrophy (DM1). Small and uncontrolled studies have focused on EDS phenotype; none have focused on nocturnal REM sleep characteristics in DM1. Our objectives were to compare polysomnographic and multiple sleep latency test (MSLT) parameters, and both tonic and phasic components of REM sleep between DM1 and controls. Forty consecutive DM1 patients and 40 sex- and age-matched controls were included. All subjects underwent overnight polysomnography followed by a MSLT. About 80% of DM1 patients complained of EDS through clinical interview: 31.4% had Epworth scores > 10, and 12.5% had objective sleepiness (latency < 8 min). Higher apnea and central apnea indexes, and a greater proportion of subjects with severe apnea/hypopnea syndrome were found in DM1. The number of SOREMP differed between DM1 and controls, one and two SOREMPs being present in 47.5% and 32.5%, and one control had one SOREMP. Higher percentages of slow wave sleep and REM sleep were found in DM1. DM1 patients had significantly more PLMW, PLMS in both NREM and REM sleep, and PLMS-associated microarousals. Higher REM density was found in DM1 with similar tendencies for either REM sleep without atonia or phasic EMG activity. This is the first case-control sleep study in DM1 to demonstrate higher frequency of daytime sleepiness and abnormalities in REM sleep regulation, with an increased daytime and nighttime REM sleep propensity, REM density, and PLMS. These data suggest a primary central sleep regulation dysfunction in DM1.

  13. [Intracellular signal transduction of endocrine organs and expanded DNA fragment size in myotonic dystrophy].

    PubMed

    Kinoshita, M; Hasegawa, T; Komori, T; Hirose, K; Tanabe, H

    1995-06-01

    The Ellsworth-Howard (EH) test was performed in 16 patients with myotonic dystrophy (DM), who were divided into two groups according to serum calcium level; Group I showing normal serum calcium (8 patients) and Group II with hypocalcemia (8 patients). Patients in Group II were recognized as having pseudohypoparathyroidism (PHP) type II and those in Group I as normal. Therefore, it was suggested that an abnormality of A kinase might be present in Group II patients. We additionally performed the thyrotropin releasing hormone (TRH) tolerance test in the same patients and 7 normal controls to examine an abnormality of C kinase. delta TSH (delta TSH: peak minus pre TSH) values in DM patients were significantly lower than those in normal controls. Moreover, delta TSH values in Group II were significantly lower than those in Group I. It was suggested that the abnormality of C kinase might be present in Group II patients. Taken together, our results indicated that some patients with DM might possess abnormalities of signal transduction of both A and C kinases. We compared the degree of endocrine involvement determined by both the EH test and the TRH tolerance test with expanded DNA fragment (EF) size determined by standard Southern blot analysis using an appropriate cDNA probe (cDNA25 probe). There was significant negative correlation between EF size and the results of the EH test and negative correlation between the EF size and the results of the TRH tolerance test. These findings suggested that EF size might be correlated with disease severity in affected endocrine organs.

  14. Rationally Designed Small Molecules Targeting the RNA That Causes Myotonic Dystrophy Type 1 Are Potently Bioactive

    PubMed Central

    Childs-Disney, Jessica L.; Hoskins, Jason; Rzuczek, Suzanne G.; Thornton, Charles A.; Disney, Matthew D.

    2012-01-01

    RNA is an important drug target, but it is difficult to design or discover small molecules that modulate RNA function. In the present study, we report that rationally designed, modularly assembled small molecules that bind the RNA that causes myotonic dystrophy type 1 (DM1) are potently bioactive in cell culture models. DM1 is caused when an expansion of r(CUG) repeats, or r(CUG)exp, is present in the 3′ untranslated region (UTR) of the dystrophia myotonica protein kinase (DMPK) mRNA. r(CUG)exp folds into a hairpin with regularly repeating 5′CUG/3′GUC motifs and sequester muscleblind-like 1 protein (MBNL1). A variety of defects are associated with DM1 including: (i) formation of nuclear foci, (ii) decreased translation of DMPK mRNA due to its nuclear retention, and (iii) pre-mRNA splicing defects due to inactivation of MBNL1, which controls the alternative splicing of various pre-mRNAs. Previously, modularly assembled ligands targeting r(CUG)exp were designed using information in an RNA motif-ligand database. These studies showed that a bis-benzimidazole (H) binds the 5′CUG/3′GUC motif in r(CUG)exp. Therefore, we designed multivalent ligands to bind multiple copies of this motif simultaneously in r(CUG)exp. Herein, we report that the designed compounds improve DM1-associated defects including improvement of translational and pre-mRNA splicing defects and the disruption of nuclear foci. These studies may establish a foundation to exploit other RNA targets in genomic sequence. PMID:22332923

  15. Correlation between distribution of muscle weakness, electrophysiological findings and CTG expansion in myotonic dystrophy.

    PubMed

    Khoshbakht, Roya; Soltanzadeh, Akbar; Zamani, Babak; Abdi, Siyamak; Gharagozli, Kourosh; Kahrizi, Kimia; Khoshbakht, Rahem; Nafissi, Shahriar

    2014-07-01

    Myotonic dystrophy type 1 (DM-1) is a multi-system disorder affecting the muscles, brain, cardiovascular system, endocrine system, eyes and skin. Diagnosis is made by clinical, electrodiagnostic and genetic studies. This study aimed to determine the correlation between CTG expansion and distribution of muscle weakness and clinical and electrophysiological findings. Genetically confirmed DM-1 patients presenting to Shariati Hospital between 2005 and 2011 were included in this study. Clinical, electrodiagnostic and genetic testing was performed and the correlation between CTG expansion and distribution of muscle weakness and clinical and electromyographic findings was studied. Thirty-three genetically confirmed DM-1 patients were enrolled. Myotonia, bifacial weakness and distal upper limb weakness were seen in all patients. Diabetes mellitus was found in one patient (3%), cardiac disturbance in eight (24.2%), cataracts in eight (24.2%), hypogonadism in five (15.2%), frontal baldness in 13 (39.4%), temporalis wasting in 14 (42.4%), temporomandibular joint disorder in seven (21.2%) and mental retardation in eight (24.2%). The mean number of CTG repeats, measured by Southern blot, was 8780 (range 500-15,833). A negative correlation was found between CTG expansion and age of onset. Temporalis wasting and mental retardation were positively correlated with CTG expansion. No relationship was found between weakness distribution, electromyographic findings, other systemic features and CTG expansion. In this study of DM-1 in Iran, we found a correlation between CTG expansion and age of onset, temporalis wasting and mental disability. No correlation between CTG expansion and electrodiagnostic and other clinical findings were detected.

  16. Plasma microRNAs as biomarkers for myotonic dystrophy type 1.

    PubMed

    Perfetti, Alessandra; Greco, Simona; Bugiardini, Enrico; Cardani, Rosanna; Gaia, Paola; Gaetano, Carlo; Meola, Giovanni; Martelli, Fabio

    2014-06-01

    Myotonic dystrophy type 1 (DM1) lacks non-invasive and easy to measure biomarkers, still largely relying on semi-quantitative tests for diagnostic and prognostic purposes. Muscle biopsies provide valuable data, but their use is limited by their invasiveness. microRNA (miRNAs) are small non-coding RNAs regulating gene expression that are also present in biological fluids and may serve as diseases biomarkers. Thus, we tested plasma miRNAs in the blood of 36 DM1 patients and 36 controls. First, a wide miRNA panel was profiled in a patient subset, followed by validation using all recruited subjects. We identified a signature of nine deregulated miRNAs in DM1 patients: eight miRNAs were increased (miR-133a, miR-193b, miR-191, miR-140-3p, miR-454, miR-574, miR-885-5p, miR-886-3p) and one (miR-27b) was decreased. Next, the levels of these miRNAs were used to calculate a "DM1-miRNAs score". We found that both miR-133a levels and DM1-miRNAs score discriminated DM1 from controls significantly and Receiver-Operator Characteristic curves displayed an area under the curve of 0.94 and 0.97, respectively. Interestingly, both miR-133a levels and DM1-miRNAs score displayed an inverse correlation with skeletal muscle strength and displayed higher values in more compromised patients. In conclusion, we identified a characteristic plasma miRNA signature of DM1. Although preliminary, this study indicates miRNAs as potential DM1 humoral biomarkers.

  17. Living with myotonic dystrophy; what can be learned from couples? A qualitative study.

    PubMed

    Cup, Edith H C; Kinébanian, Astrid; Satink, Ton; Pieterse, Allan J; Hendricks, Henk T; Oostendorp, Rob A B; van der Wilt, Gert Jan; van Engelen, Baziel G M

    2011-07-13

    Myotonic dystrophy type 1 (MD1) is one of the most prevalent neuromuscular diseases, yet very little is known about how MD1 affects the lives of couples and how they themselves manage individually and together. To better match health care to their problems, concerns and needs, it is important to understand their perspective of living with this hereditary, systemic disease. A qualitative study was carried out with a purposive sample of five middle-aged couples, including three men and two women with MD1 and their partners. Fifteen in-depth interviews with persons with MD1, with their partners and with both of them as a couple took place in the homes of the couples in two cities and three villages in the Netherlands in 2009. People with MD1 associate this progressive, neuromuscular condition with decreasing abilities, describing physical, cognitive and psychosocial barriers to everyday activities and social participation. Partners highlighted the increasing care giving burden, giving directions and using reminders to compensate for the lack of initiative and avoidant behaviour due to MD1. Couples portrayed the dilemmas and frustrations of renegotiating roles and responsibilities; stressing the importance of achieving a balance between individual and shared activities. All participants experienced a lack of understanding from relatives, friends, and society, including health care, leading to withdrawal and isolation. Health care was perceived as fragmentary, with specialists focusing on specific aspects of the disease rather than seeking to understand the implications of the systemic disorder on daily life. Learning from these couples has resulted in recommendations that challenge the tendency to treat MD1 as a condition with primarily physical impairments. It is vital to listen to couples, to elicit the impact of MD1, as a multisystem disorder that influences every aspect of their life together. Couple management, supporting the self-management skills of both

  18. Progression of muscle histopathology but not of spliceopathy in myotonic dystrophy type 2.

    PubMed

    Cardani, Rosanna; Giagnacovo, Marzia; Rossi, Giulia; Renna, Laura V; Bugiardini, Enrico; Pizzamiglio, Chiara; Botta, Annalisa; Meola, Giovanni

    2014-12-01

    Myotonic dystrophy type 2 (DM2) is an autosomal dominant progressive disease involving skeletal and cardiac muscle and brain. It is caused by a tetranucleotide repeat within the first intron of the CNBP gene that leads to an alteration of the alternative splicing of several genes. To understand the molecular mechanisms that play a role in DM2 progression, the evolution of skeletal muscle histopathology and biomolecular findings in successive biopsies have been studied. Biceps brachii biopsies from 5 DM2 patients who underwent two successive biopsies at different years of age have been used. Muscle histopathology has been assessed on sections immunostained with fast or slow myosin. FISH in combination with MBNL1-immunofluorescence has been performed to evaluate ribonuclear inclusion and MBNL1 foci dimensions in myonuclei. Gene and protein expression and alteration of alternative splicing of several genes have been evaluated over time. All DM2 patients examined show a worsening of muscle histopathology and an increase of foci dimensions over time. The progressive worsening of myotonia in DM2 patients may be due to the decrease of CLCN1 mRNA observed in all patients examined. However, a worsening of alternative splicing alterations has not been evidenced over time. The data obtained in this study confirm that DM2 is a slow progression disease since histological and biomolecular alterations observed in skeletal muscle are minimal even after 10-year interval. The data indicate that muscle morphological alterations evolve more rapidly over time than the molecular changes thus indicating that muscle biopsy is a more sensitive tool than biomolecular markers to assess disease progression at muscle level.

  19. Rational and modular design of potent ligands targeting the RNA that causes myotonic dystrophy 2.

    PubMed

    Lee, Melissa M; Pushechnikov, Alexei; Disney, Matthew D

    2009-05-15

    Most ligands targeting RNA are identified through screening a therapeutic target for binding members of a ligand library. A potential alternative way to construct RNA binders is through rational design using information about the RNA motifs ligands prefer to bind. Herein, we describe such an approach to design modularly assembled ligands targeting the RNA that causes myotonic dystrophy type 2 (DM2), a currently untreatable disease. A previous study identified that 6'-N-5-hexynoate kanamycin A (1) prefers to bind 2x2 nucleotide, pyrimidine-rich RNA internal loops. Multiple copies of such loops are found in the RNA hairpin that causes DM2. The 1 ligand was then modularly displayed on a peptoid scaffold with varied number and spacing to target several internal loops simultaneously. Modularly assembled ligands were tested for binding to a series of RNAs and for inhibiting the formation of the toxic DM2 RNA-muscleblind protein (MBNL-1) interaction. The most potent ligand displays three 1 modules, each separated by four spacing submonomers, and inhibits the formation of the RNA-protein complex with an IC(50) of 25 nM. This ligand has higher affinity and is more specific for binding the DM2 RNA than MBNL-1. It binds the DM2 RNA at least 30 times more tightly than related RNAs and 15-fold more tightly than MBNL-1. A related control peptoid displaying 6'-N-5-hexynoate neamine (2) is >100-fold less potent at inhibiting the RNA-protein interaction and binds to DM2 RNA >125-fold more weakly. Uptake studies into a mouse myoblast cell line also show that the most potent ligand is cell permeable.

  20. Rationally designed small molecules targeting the RNA that causes myotonic dystrophy type 1 are potently bioactive.

    PubMed

    Childs-Disney, Jessica L; Hoskins, Jason; Rzuczek, Suzanne G; Thornton, Charles A; Disney, Matthew D

    2012-05-18

    RNA is an important drug target, but it is difficult to design or discover small molecules that modulate RNA function. In the present study, we report that rationally designed, modularly assembled small molecules that bind the RNA that causes myotonic dystrophy type 1 (DM1) are potently bioactive in cell culture models. DM1 is caused when an expansion of r(CUG) repeats, or r(CUG)(exp), is present in the 3' untranslated region (UTR) of the dystrophia myotonica protein kinase (DMPK) mRNA. r(CUG)(exp) folds into a hairpin with regularly repeating 5'CUG/3'GUC motifs and sequesters muscleblind-like 1 protein (MBNL1). A variety of defects are associated with DM1, including (i) formation of nuclear foci, (ii) decreased translation of DMPK mRNA due to its nuclear retention, and (iii) pre-mRNA splicing defects due to inactivation of MBNL1, which controls the alternative splicing of various pre-mRNAs. Previously, modularly assembled ligands targeting r(CUG)(exp) were designed using information in an RNA motif-ligand database. These studies showed that a bis-benzimidazole (H) binds the 5'CUG/3'GUC motif in r(CUG)(exp.) Therefore, we designed multivalent ligands to bind simultaneously multiple copies of this motif in r(CUG)(exp). Herein, we report that the designed compounds improve DM1-associated defects including improvement of translational and pre-mRNA splicing defects and the disruption of nuclear foci. These studies may establish a foundation to exploit other RNA targets in genomic sequence.

  1. Age, conduction defects and restrictive lung disease independently predict cardiac events and death in myotonic dystrophy.

    PubMed

    Kaminsky, Pierre; Brembilla-Perrot, Béatrice; Pruna, Lelia; Poussel, Mathias; Chenuel, Bruno

    2013-01-20

    The aim of the study was to identify, in addition to conduction defects, possible predictors of cardiac events and death in patients with myotonic dystrophy (DM1). A retrospective observational cohort study was undertaken. Baseline clinical and non-invasive cardiac and respiratory investigations were obtained from 107 DM1 patients, who were regularly re-examined. Primary end-points were occurrence of cardiac events (pacemaker implantation or tachyarrhythmia) or death. Probability of an event was calculated using the Kaplan-Meier method, while contributing factors were assessed using univariate and multivariate (Cox model) analyses. Cardiac events occurred in 34 patients (29%). Age, muscular impairment, infantile onset, restrictive lung disease (RLD), ECG conduction defects, left ventricular ejection fraction (LVEF) below 50%, and arrhythmia detected during Holter monitoring were predictors of cardiac events. Multivariate analysis indicated that age, RLD, ECG conduction defects, Holter arrhythmia and LVEF remained independent predictors. Probability of cardiac events was 2.5% (5%CI: 0-7%) at 1 year and 6% (5%CI: 0-14%) at 3 years in patients younger than 42 years with normal ECG, Holter, LVEF and lung volumes. Advancing age, distal or proximal weakness and RLD characterized all non-survivors (n=14). Cardiac events or death are predicted not only by conduction defects or cardiomyopathy in DM1, but also by RLD, muscular disability and advancing age. Addition of these criteria should modulate time intervals for patient follow-up examinations. In young patients with normal baseline investigations, screening investigations every 2 or 3 years seem to be sufficient. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  2. Clinical predictors of conduction disease progression in type I myotonic muscular dystrophy.

    PubMed

    Nazarian, Saman; Wagner, Kathryn R; Caffo, Brian S; Tomaselli, Gordon F

    2011-02-01

    Patients with type I myotonic muscular dystrophy (DM1) are at risk for sudden death due to atrioventricular conduction block. We sought to characterize the trends and predictors of time-dependent electrocardiographic (ECG) variations in patients with DM1. Seventy patients with DM1 underwent standard electrocardiography at first evaluation and routine and symptom prompted follow-up. Individual variations in ECG conduction intervals were assessed using spaghetti plots. Clinical predictors of conduction disease progression were assessed using multivariate random effects regression models of panel data clustered by patient and adjusted for heart rate. Substantial individual variability was noted in time-dependent changes in PR, QRS, and QTc intervals of patients with DM1. Changes in the QTc interval were closely associated with prolongation of the QRS interval. Age, the presence of paroxysmal atrial flutter or fibrillation, and the number of cytosine-thymine-guanine (CTG) repeats were independent positive predictors of time-dependent PR and QRS prolongation during long-term follow-up. Female sex was negatively associated with PR prolongation but positively associated with QTc prolongation. Lower left ventricular ejection fraction was associated with greater QRS interval progression during long-term follow-up but was not predictive of PR interval progression. Patients with DM1 can develop rapid changes in cardiac conduction intervals. Paroxysmal atrial flutter or fibrillation, older age, and larger CTG expansions predict greater time-dependent PR and QRS interval prolongation and warrant particular attention in the arrhythmic evaluation of this high risk patient subset. ©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc.

  3. Reduction of the rate of Protein Translation in Patients with Myotonic Dystrophy 2

    PubMed Central

    Huichalaf, Claudia; Schoser, Benedikt; Schneider-Gold, Christiane; Jin, Bingwen; Sarkar, Partha; Timchenko, Lubov

    2012-01-01

    Myotonic Dystrophy 2 (DM2) is an autosomal dominant, multisystem disease, which primarily affects skeletal muscle. DM2 is caused by CCTGn expansion in the intron 1 of the ZNF9 gene. Expression of the mutant CCUGn RNA changes RNA processing in patients with DM2; however, the role of ZNF9 protein in DM2 pathology has been not elucidated. ZNF9 has been shown to regulate cap-dependent and cap-independent translation. We have examined a possible role of ZNF9 in the regulation of translation in DM2 patients. We have found that ZNF9 interacts with the 5′ UTRs of TOP (terminal oligopyrimidine tract) mRNAs encoding human ribosomal protein, RPS17, poly(A)-binding protein, PABP1, and elongation factors, eEF1A and eEF2. The binding activity of ZNF9 toward these TOP-containing 5′ UTRs is reduced in DM2 muscle. Consistent with the reduction of this activity, the levels of RPS17, PABP, eEF1A and eEF2 proteins are also diminished in DM2 muscle. The reduction of ZNF9 RNA-binding activity in DM2 correlates with a decrease of ZNF9 protein levels in cytoplasm of DM2 muscle cells. We have found that the reduction of ZNF9 is caused by expression of the mutant CCUG repeats. This decrease of proteins of translational apparatus in DM2 correlates with a reduction of a rate of protein synthesis in myoblasts from DM2 patients. We found that the ectopic expression of ZNF9 in DM2 myoblasts corrects rate of protein synthesis suggesting that the alterations in CCUG-ZNF9-TOP mRNAs pathway are responsible for the reduction of the rate of protein translation in DM2 muscle cells. PMID:19605641

  4. Detection of large expansions in myotonic dystrophy type 1 using triplet primed PCR

    PubMed Central

    Singh, Susmita; Zhang, Amy; Dlouhy, Stephen; Bai, Shaochun

    2014-01-01

    Myotonic dystrophy type 1 (DM1) is an autosomal dominant neuromuscular disease caused by expansion of a CTG trinucleotide repeat in the DMPK gene. Methodology for genetic testing of DM1 is currently not optimal, in particular for the early-onset patients in pediatric populations where large expanded (CTG)n alleles are usually common. Individuals who are homozygous for a normal allele and individuals who are heterozygous for one normal and one large expanded allele are indistinguishable by conventional PCR, as both generate a single product of the normal allele. Thus, reflex Southern blot has often been needed to distinguish these cases. With the aim to decrease the need for reflex Southern blot tests, a novel, single-tube CTG repeat primed PCR technology was designed to distinguish the true homozygous patients from the individuals whose large alleles are missed by conventional PCR. The method utilizes two gene-specific primers that flank the triplet repeat region and a third primer set complementary to the repeated region to detect the large alleles. Compared to traditional PCR, this novel Triplet-repeat Primed PCR can detect the presence of large expanded alleles with demonstrating a ladder pattern. Using this single-step protocol, 45 specimens were tested. The alleles with sizes~í~85 repeats were determined by the gene specific primers. 13 abnormal alleles, which were missed by conventional PCR, were successfully detected by the Triplet-repeat Primed PCR. All the abnormal alleles were confirmed and measured by Southern Blot analysis. In summary, optimized Triplet-Primed PCR (TP-PCR) can accurately detect the presence of the large expanded alleles. With the ability to distinguish the true homozygous patients from the false negative homozygous individuals, the application of the optimized TP-PCR can significantly reduce the need of Southern Blot tests. PMID:24795756

  5. Perceived functioning and disability in adults with myotonic dystrophy type 1: a survey according to the International Classification Of Functioning, Disability and Health.

    PubMed

    Kierkegaard, Marie; Harms-Ringdahl, Karin; Widén Holmqvist, Lotta; Tollbäck, Anna

    2009-06-01

    The purpose of this study was to describe and analyse self-rated perceived functioning, disability and environmental facilitators/barriers with regard to disease severity, using the International Classification of Functioning, Disability and Health (ICF) checklist, in adults with myotonic dystrophy type 1. Cross-sectional design. Forty-one women and 29 men with myotonic dystrophy type 1. A modified ICF checklist was used for self-rating of perceived problems in 29 body-function categories, difficulties in 52 activity and participation categories, and facilitators/barriers in 23 environmental-factor categories according to the verbal anchors of the ICF qualifiers. Disease severity classification was based on the muscular impairment rating scale. Of the persons with myotonic dystrophy type 1, 80% perceived problems of excessive daytime sleepiness, 76% of muscle power, and 66% of energy and drive functions, while over 59% perceived difficulties in physically demanding mobility activities. Disabilities in mobility, self-care and domestic life were more frequently reported by persons with severe disease. Support from the immediate family, medicines and social security services were perceived as facilitators for 50-60% of the participants. Disabilities and important environmental facilitators in adults with myotonic dystrophy type 1 were identified, and this clinically-relevant information can be used for developing health services for people with this condition.

  6. Effect of the myotonic dystrophy expanded (CTG){sub n} repeat on the transcripts of DMPK alleles

    SciTech Connect

    Krahe, R.; Narayana, L.; Sciliano, M.J.

    1994-09-01

    Myotonic dystrophy (DM) is a pleiotropic, autosomal dominantly inherited neuromuscular disease. The clinical phenotype is associated with an unstable (CTG){sub n} repeat in the 3{prime} untranslated region of the candidate gene, DM protein kinase (DMPK). The size of the unstable repeat generally increases through successive generations and correlates to a reasonable degree with the phenotype in a given family. In various studies both decreased and increased levels of mutant steady-state DMPK mRNA and protein levels have been observed and related to (CTG){sub n} repeat expansion. This has led to different proposals to explain the molecular disease mechanism (gene-dosage vs. gain-of-function effect). Using allele-specific transcript amplification, comparative and quantitative MIMIC RT-PCR, and mRNA stability assays for the exon 9-10 region of the DMPK gene, we report co-equal expression of mutant and normal alleles at both hnRNA and mRNA levels. Identical levels of overall mRNA and no allele-specific differences in mRNA stability were seen in adult-onset and congenital DM patients compared to normal controls. The expanded repeat did not appear to interfere with transcriptional initiation or increase or decrease the stability of either primary or mature transcript of the mutant and normal DMPK allele. Similar results were obtained for two homozygous DM sisters. Pairs of somatic cell hybrids - one of the pair containing the chromosome with the expanded (CTG){sub n} repeat, the other with the normal repeat - were generated. We observed equal hnRNA, but significantly reduced mRNA levels for DMPK from exon 8 to 15 for the hybrid containing the expanded repeat, suggesting aberrant processing of mutant hnRNA to mRNA. Therefore, the results of current studies on the effect of the expanded (CTG){sub n} repeat on post-transcriptional events such as splicing downstream of the exon 10 will be reported.

  7. Induction and reversal of myotonic dystrophy type 1 pre-mRNA splicing defects by small molecules.

    PubMed

    Childs-Disney, Jessica L; Stepniak-Konieczna, Ewa; Tran, Tuan; Yildirim, Ilyas; Park, HaJeung; Chen, Catherine Z; Hoskins, Jason; Southall, Noel; Marugan, Juan J; Patnaik, Samarjit; Zheng, Wei; Austin, Chris P; Schatz, George C; Sobczak, Krzysztof; Thornton, Charles A; Disney, Matthew D

    2013-01-01

    The ability to control pre-mRNA splicing with small molecules could facilitate the development of therapeutics or cell-based circuits that control gene function. Myotonic dystrophy type 1 is caused by the dysregulation of alternative pre-mRNA splicing due to sequestration of muscleblind-like 1 protein (MBNL1) by expanded, non-coding r(CUG) repeats (r(CUG)(exp)). Here we report two small molecules that induce or ameliorate alternative splicing dysregulation. A thiophene-containing small molecule (1) inhibits the interaction of MBNL1 with its natural pre-mRNA substrates. Compound (2), a substituted naphthyridine, binds r(CUG)(exp) and displaces MBNL1. Structural models show that 1 binds MBNL1 in the Zn-finger domain and that 2 interacts with UU loops in r(CUG)(exp). This study provides a structural framework for small molecules that target MBNL1 by mimicking r(CUG)(exp) and shows that targeting MBNL1 causes dysregulation of alternative splicing, suggesting that MBNL1 is thus not a suitable therapeutic target for the treatment of myotonic dystrophy type 1.

  8. Congenital nutritional muscular dystrophy in a beef calf.

    PubMed

    Abutarbush, Sameeh M; Radostits, Otto M

    2003-09-01

    A 13-hour-old Aberdeen-Angus was involuntarily recumbent since birth. Congenital nutritional muscular dystrophy was suspected based on clinical findings, increased serum creatine kinase, and decreased serum vitamin E and selenium levels. Recovery followed after supportive therapy and parenteral vitamin E and selenium. Reports of this disease in newborn calves are unusual.

  9. Global muscular dystrophy research: A 25-year bibliometric perspective.

    PubMed

    Ram, Shri

    2017-01-01

    Muscular dystrophy is a genetic disorder leading to progressive weakness of muscles caused due to dysfunction in or lack of protein in muscle cells. The prevalence of muscular dystrophy has been observed globally and is becoming a critical area of study for better health services. The purpose of the study is to analyze the research strength of muscular dystrophy using bibliographic literature. A quantitative literature analysis was carried out on muscular dystrophy from 1991 to 2015 for assessing the global research trends. This literature-based study was conducted using the documents retrieved from the Science Citation Index using the keywords: Duchenne Muscular Dystrophy (DMD), Becker Muscular Dystrophy (BMD), Congenital Muscular Dystrophy (CMD), Myotonic Dystrophy, Emery-Dreifuss Muscular Dystrophy, Facioscapulohumeral Muscular Dystrophy, Oculopharyngeal Muscular Dystrophy, and Limb-Girdle Muscular Dystrophy. Analysis was done for annual productivity of publication, authorship, collaboration, country performance, citation frequency, characteristics of most cited document, journal productivity, etc.

  10. Effects of 1-month withdrawal of ventilatory support in hypercapnic myotonic dystrophy type 1.

    PubMed

    O'Donoghue, Fergal J; Borel, Jean-Christian; Dauvilliers, Yves; Levy, Patrick; Tamisier, Renaud; Pépin, Jean-Louis

    2017-10-01

    The benefits of domiciliary non-invasive ventilation (NIV) in myotonic dystrophy type 1 (DM1) are unclear. We sought to determine the effects of elective discontinuation of ventilatory support for 1 month in DM1 patients receiving NIV for chronic hypercapnic respiratory failure. At baseline, 12 patients underwent polysomnography, and assessment of subjective (Epworth Sleepiness Scale) and objective (Oxford Sleep Resistance Test) sleepiness, fatigue (Fatigue Severity Scale), respiratory function including muscle strength, arterial blood gas (ABG), hypercapnic ventilatory response (HCVR), Blood Pressure, peripheral arterial tonometry (PAT) and pulse wave velocity (PWV). They also completed the SF36. Testing was repeated (Visit 2) 1 month after elective cessation of NIV and again (Visit 3) 1 month after NIV reintroduction. No changes were seen in SF36, sleepiness or fatigue, respiratory function, muscle strength nor HCVR. Likewise, there were no changes in Blood Pressure, PAT or PWV. Mean nocturnal SpO2 deteriorated off NIV and improved on resumption (mean ± SD = 95.02 ± 1.90%, 92.23 ± 3.61% and 95.08 ± 2.28%, P = 0.006 change Visit 1 to Visit 2, 0.009 Visit 2 to Visit 3). Daytime PaCO2 (arterial partial pressure of carbon dioxide) was 43.13 ± 4.20 mm Hg, 46.28 ± 2.25 mm Hg and 43.87 ± 2.85 mm Hg, P = 0.056 and 0.017 over the same intervals. DM1 patients derive little benefit in symptoms or quality of life from NIV. Nocturnal and diurnal ventilatory functions deteriorate slightly off NIV for 1 month, but this does not appear to be due to changes in HCVR or respiratory function. HCVR changes may be of primary CNS origin given stability on or off NIV. © 2017 Asian Pacific Society of Respirology.

  11. Computational Investigation of RNA CUG Repeats Responsible for Myotonic Dystrophy 1

    PubMed Central

    2015-01-01

    Myotonic Dystrophy 1 (DM1) is a genetic disease caused by expansion of CTG repeats in DNA. Once transcribed, these repeats form RNA hairpins with repeating 1×1 nucleotide UU internal loop motifs, r(CUG)n, which attract muscleblind-like 1 (MBNL1) protein leading to the disease. In DM1 CUG can be repeated thousands of times, so these structures are intractable to characterization using structural biology. However, inhibition of MBNL1-r(CUG)n binding requires a detailed analysis of the 1×1 UU internal loops. In this contribution we employ regular and umbrella sampling molecular dynamics (MD) simulations to describe the structural and thermodynamic properties of 1×1 UU internal loops. Calculations were run on a reported crystal structure and a designed system, which mimics an infinitely long RNA molecule with continuous CUG repeats. Two-dimensional (2D) potential of mean force (PMF) surfaces were created by umbrella sampling, and the discrete path sampling (DPS) method was utilized to investigate the energy landscape of 1×1 UU RNA internal loops, revealing that 1×1 UU base pairs are dynamic and strongly prefer the anti–anti conformation. Two 2D PMF surfaces were calculated for the 1×1 UU base pairs, revealing several local minima and three syn–anti ↔ anti–anti transformation pathways. Although at room temperature the syn–anti ↔ anti–anti transformation is not observed on the MD time scale, one of these pathways dominates the dynamics of the 1×1 UU base pairs in temperature jump MD simulations. This mechanism has now been treated successfully using the DPS approach. Our results suggest that local minima predicted by umbrella sampling calculations could be stabilized by small molecules, which is of great interest for future drug design. Furthermore, distorted GC/CG conformations may be important in understanding how MBNL1 binds to RNA CUG repeats. Hence we provide new insight into the dynamic roles of RNA loops and their contributions to presently

  12. Overexpression of microRNA-206 in the skeletal muscle from myotonic dystrophy type 1 patients

    PubMed Central

    2010-01-01

    Background MicroRNAs are highly conserved, noncoding RNAs involved in post-transcriptional gene silencing. They have been shown to participate in a wide range of biological processes, including myogenesis and muscle regeneration. The goal of this study is to test the hypothesis that myo-miRs (myo = muscle + miR = miRNA) expression is altered in muscle from patients affected by myotonic dystrophy type 1 (DM1), the most frequently inherited neuromuscular disease in adults. In order to gain better insights about the role of miRNAs in the DM1 pathogenesis, we have also analyzed the muscular expression of miR-103 and miR-107, which have been identified in silico as attractive candidates for binding to the DMPK mRNA. Methods To this aim, we have profiled the expression of miR-133 (miR-133a, miR-133b), miR-1, miR-181 (miR-181a, miR-181b, miR-181c) and miR-206, that are specifically induced during myogenesis in cardiac and skeletal muscle tissues. miR-103 and miR-107, highly expressed in brain, heart and muscle have also been included in this study. QRT-PCR experiments have been performed on RNA from vastus lateralis biopsies of DM1 patients (n = 7) and control subjects (n = 4). Results of miRNAs expression have been confirmed by Northern blot, whereas in situ hybridization technique have been performed to localize misexpressed miRNAs on muscle sections from DM1 and control individuals. Results Only miR-206 showed an over-expression in 5 of 7 DM1 patients (threshold = 2, fold change between 1.20 and 13.22, average = 5.37) compared to the control group. This result has been further confirmed by Northern blot analysis (3.37-fold overexpression, R2 = 0.89). In situ hybridization localized miR-206 to nuclear site both in normal and DM1 tissues. Cellular distribution in DM1 tissues includes also the nuclear regions of centralized nuclei, with a strong signal corresponding to nuclear clumps. Conclusions This work provides, for the first time, evidences about miRNAs misexpression

  13. Changes in pain-related beliefs, coping, and catastrophizing predict changes in pain intensity, pain interference, and psychological functioning in individuals with Myotonic Muscular Dystrophy and Facioscapulohumeral Dystrophy

    PubMed Central

    Nieto, Rubén; Raichle, Katherine A.; Jensen, Mark P.; Miró, Jordi

    2011-01-01

    Objectives The primary aim of this study was to test hypothesized associations between changes in psychological variables (i.e., pain beliefs, catastrophizing and coping strategies) and changes in pain intensity and related adjustment (i.e., pain interference and psychological functioning) in individuals with Myotonic Muscular Dystrophy (MMD) and Facioscapulohumeral Muscular Dystrophy (FSHD). Methods A sample of 107 adults with a diagnosis of MMD or FSHD, reporting pain in the past three months, completed assessments at two time-points, separated by about 24 months. Results Results showed that changes in pain-related psychological variables were significantly associated with changes in psychological functioning, pain intensity and pain interference. Specifically, increases in the belief that emotion influences pain, and catastrophizing were associated with decreases in psychological functioning. Increases in the coping strategies of asking for assistance and resting, and the increases of catastrophizing were associated with increases in pain intensity. Finally, increases in pain intensity and asking for assistance were associated with increases in pain interference. Discussion The results support the utility of the biopsychosocial model of pain for understanding pain and its impact in individuals with MMD or FSHD. These findings may inform the design and implementation of psychosocial pain treatments for people with muscular dystrophy and chronic pain. PMID:21642844

  14. Tibialis anterior muscle needle biopsy and sensitive biomolecular methods: a useful tool in myotonic dystrophy type 1.

    PubMed

    Iachettini, S; Valaperta, R; Marchesi, A; Perfetti, A; Cuomo, G; Fossati, B; Vaienti, L; Costa, E; Meola, G; Cardani, R

    2015-10-26

    Myotonic dystrophy type 1 (DM1) is a neuromuscular disorder caused by a CTG repeat expansion in 3'UTR of DMPK gene. This mutation causes accumulation of toxic RNA in nuclear foci leading to splicing misregulation of specific genes. In view of future clinical trials with antisense oligonucleotides in DM1 patients, it is important to set up sensitive and minimally-invasive tools to monitor the efficacy of treatments on skeletal muscle. A tibialis anterior (TA) muscle sample of about 60 mg was obtained from 5 DM1 patients and 5 healthy subjects through a needle biopsy. A fragment of about 40 mg was used for histological examination and a fragment of about 20 mg was used for biomolecular analysis. The TA fragments obtained with the minimally-invasive needle biopsy technique is enough to perform all the histopathological and biomolecular evaluations useful to monitor a clinical trial on DM1 patients.

  15. Skeletal muscle features in myotonic dystrophy and sarcopenia: do similar nuclear mechanisms lead to skeletal muscle wasting?

    PubMed

    Malatesta, M

    2012-08-10

    In the cell nucleus, the gene primary transcripts undergo molecular processing to generate mature RNAs, which are finally exported to the cytoplasm. These mRNA maturation events are chronologically and spatially ordered, and mostly occur on distinct ribonucleoprotein (RNP)-containing structures. Defects in the mRNA maturation pathways have been demonstrated in myotonic dystrophy type 1 (DM1) and type 2 (DM2) whose characteristic multisystemic features are caused by the expansion of two distinct nucleotide sequences: (CTG)n in the DMPK gene on chromosome 19q13 in DM1, and (CCTG)n in the ZNF9 gene on chromosome 3q21 in DM2. By combining biomolecular and cytochemical techniques, it has been shown that the basic mechanisms of DMs reside in the accumulation of CUG- or CCUG-containing transcripts in intranuclear foci where several RNA-binding proteins necessary for the physiological processing of pre-mRNA are sequestered. Moreover, a nucleoplasmic accumulation of splicing and cleavage factors has been found in DMs. This suggests that the dystrophic phenotype could depend on a general alteration of the pre-mRNA post-transcriptional pathway. Interestingly, the accumulation of pre-mRNA processing factors in the myonuclei of DM1 and DM2 patients is reminiscent of the nuclear alterations typical of sarcopenia, i.e., the loss of muscle mass and function which physiologically occurs during ageing. Consistently, in an in vitro study, we observed that satellite-cell-derived DM2 myoblasts show cell senescence alterations and impairment of the pre-mRNA maturation pathways earlier than the myoblasts from healthy patient. These results suggest possible common cellular mechanisms responsible for skeletal muscle wasting in sarcopenia and in myotonic dystrophy.

  16. Effects of hand-training in persons with myotonic dystrophy type 1--a randomised controlled cross-over pilot study.

    PubMed

    Aldehag, Anna; Jonsson, Hans; Lindblad, Jan; Kottorp, Anders; Ansved, Tor; Kierkegaard, Marie

    2013-10-01

    To investigate the effects of a hand-training programme on grip, pinch and wrist force, manual dexterity and activities of daily living, in adults with myotonic dystrophy type 1 (DM1). In this randomised controlled trial with a crossover design, 35 adults with DM1 were, after stratification for grip force, assigned by lot to two groups. Group A started with 12 weeks of hand training, while group B had no intervention. After a wash-out period of 12 weeks, where none received training, the order was reversed. The Grippit® was used as primary outcome measure and the hand-held Microfet2™ myometer, the Purdue Pegboard, the Canadian Occupational Performance Measure (COPM) and the Assessment of Motor and Process Skills (AMPS) were secondary outcome measures. Assessments were performed before and after training and control periods, i.e. four times altogether. Ten persons dropped out and 13 had acceptable adherence. Intention-to-treat analyses revealed significant intervention effects for isometric wrist flexor force (p = 0.048), and for COPM performance (p = 0.047) and satisfaction (p = 0.027). On an individual level, improvements were in general showed after a training period. The hand-training programme had positive effects on wrist flexor force and self-perception of occupational performance, and of satisfaction with performance. No evident detrimental effects were shown. Myotonic dystrophy type 1 (DM1) is a slowly progressive neuromuscular disease characterised by myotonia and muscle weakness and wasting. People with DM1 are often concerned about their ability to carry out ADL and to participate in, e.g. work, sports and hobbies when they gradually become weaker. This pilot study showed that a hand-training programme improved wrist flexor force and self-perception and satisfaction of occupational performance. Resistance training of hand muscles with a silicon-based putty can be a therapy option for people with DM1 in clinical practise.

  17. Muscular Dystrophy

    MedlinePlus

    ... in Duchenne muscular dystrophy. Dev. Med. Child Neurol. Mar 1995;37(3):260-269. 4. Centers for ... DM1) . The International Myotonic Dystrophy Consortium (IDMC). Neurology. Mar 28 2000;54(6):1218-1221. 5. Harper ...

  18. Prenatal diagnosis of congenital myopathies and muscular dystrophies.

    PubMed

    Massalska, D; Zimowski, J G; Bijok, J; Kucińska-Chahwan, A; Łusakowska, A; Jakiel, G; Roszkowski, T

    2016-09-01

    Congenital myopathies and muscular dystrophies constitute a genetically and phenotypically heterogeneous group of rare inherited diseases characterized by muscle weakness and atrophy, motor delay and respiratory insufficiency. To date, curative care is not available for these diseases, which may severely affect both life-span and quality of life. We discuss prenatal diagnosis and genetic counseling for families at risk, as well as diagnostic possibilities in sporadic cases. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Anaesthetic problems in myotonic dystrophy. A case report and review of the Aberdeen experience comprising 48 general anaesthetics in a further 16 patients.

    PubMed

    Aldridge, L M

    1985-11-01

    A previously undiagnosed case of myotonic dystrophy presenting with apnoea of 2.5 h duration following thiopentone is described. A review of the anaesthetic outcome from 49 operations in 17 patients with myotonic dystrophy in the Aberdeen area is presented. The type of operation and intra- and postoperative problems are analysed. The results reveal a 52% complication rate in previously diagnosed cases and a 35% complication rate in undiagnosed cases. In the series, 29% of the anaesthetics were administered to symptomatic patients before formal diagnosis. To avoid potential hazards it behoves the anaesthetist to remain alert to the possibility of the undiagnosed disease. The symptomatology and associated findings of the 17 patients at initial diagnosis are presented. The literature has been reviewed and anaesthetic implications noted.

  20. Most expression and splicing changes in myotonic dystrophy type 1 and type 2 skeletal muscle are shared with other muscular dystrophies.

    PubMed

    Bachinski, Linda L; Baggerly, Keith A; Neubauer, Valerie L; Nixon, Tamara J; Raheem, Olayinka; Sirito, Mario; Unruh, Anna K; Zhang, Jiexin; Nagarajan, Lalitha; Timchenko, Lubov T; Bassez, Guillaume; Eymard, Bruno; Gamez, Josep; Ashizawa, Tetsuo; Mendell, Jerry R; Udd, Bjarne; Krahe, Ralf

    2014-03-01

    The prevailing pathomechanistic paradigm for myotonic dystrophy (DM) is that aberrant expression of embryonic/fetal mRNA/protein isoforms accounts for most aspects of the pleiotropic phenotype. To identify aberrant isoforms in skeletal muscle of DM1 and DM2 patients, we performed exon-array profiling and RT-PCR validation on the largest DM sample set to date, including Duchenne, Becker and tibial muscular dystrophy (NMD) patients as disease controls, and non-disease controls. Strikingly, most expression and splicing changes in DM patients were shared with NMD controls. Comparison between DM and NMD identified almost no significant differences. We conclude that DM1 and DM2 are essentially identical for dysregulation of gene expression, and DM expression changes represent a subset of broader spectrum dystrophic changes. We found no evidence for qualitative splicing differences between DM1 and DM2. While some DM-specific splicing differences exist, most of the DM splicing differences were also seen in NMD controls. SSBP3 exon 6 missplicing was observed in all diseased muscle and led to reduced protein. We conclude there is no widespread DM-specific spliceopathy in skeletal muscle and suggest that missplicing in DM (and NMD) may not be the driving mechanism for the muscle pathology, since the same pathways show expression changes unrelated to splicing.

  1. Comparison of Pulmonary Functions at Onset of Ventilatory Insufficiency in Patients With Amyotrophic Lateral Sclerosis, Duchenne Muscular Dystrophy, and Myotonic Muscular Dystrophy

    PubMed Central

    Cho, Han Eol; Lee, Jang Woo; Kang, Seong Woong; Choi, Won Ah; Oh, Hyeonjun

    2016-01-01

    Objective To evaluate pulmonary functions of patients with amyotrophic lateral sclerosis (ALS), Duchenne muscular dystrophy (DMD), and myotonic muscular dystrophy (MMD) at the onset of ventilatory insufficiency. Methods This retrospective study included ALS, DMD, and MMD patients with regular outpatient clinic follow-up in the Department of Rehabilitation Medicine at Gangnam Severance Hospital before the application of non-invasive positive pressure ventilation (NIPPV). The patients were enrolled from August 2001 to March 2014. If patients experienced ventilatory insufficiency, they were treated with NIPPV, and their pulmonary functions were subsequently measured. Results Ninety-four DMD patients, 41 ALS patients, and 21 MMD patients were included in the study. The mean SpO2 was lower in the MMD group than in the other two groups. The mean forced vital capacity (FVC) in the supine position was approximately low to mid 20% on average in DMD and ALS patients, whereas it was 10% higher in MMD patients. ALS patients showed a significantly lower FVC in the supine position than in the sitting position. Maximal insufflation capacity, unassisted peak cough flow, maximum inspiratory pressure (MIP), and maximum expiratory pressure (MEP) were significantly higher in MMD group than in the other groups. MEP was significantly the lowest in DMD patients, followed by in ALS, and MMD patients, in order. Conclusion Disease-specific values of pulmonary function, including FVC, MEP, and MIP, can be accurately used to assess the onset of ventilatory insufficiency in patients with ALS, DMD, and MMD. PMID:26949672

  2. Muscular myopathies other than myotonic dystrophy also associated with (CTG)n expansion at the DMPK locus

    PubMed Central

    Mohan, Vasavi; Ahuja, Y. R.; Hasan, Qurratulain

    2012-01-01

    Objective: Assess triplet repeat expansion (CTG)n at the ‘dystrophia-myotonica protein kinase’ (DMPK) locus in muscular myopathies to elucidate its role in myopathic symptoms and enable genetic counseling and prenatal diagnosis in families. Methods and Results: Individuals with symptoms of myopathy, hypotonia and controls selected randomly from the population were evaluated for triplet repeat expansion of (CTG)n repeats in the 3’untranslated region (UTR) of DMPK gene, the causative mutation in myotonic dystrophy (DM). DNA was isolated from peripheral blood of 40 individuals; they presented symptoms of muscle myopathy (n = 11), muscle hypotonia (n = 4), members of their families (n = 5) and control individuals from random population (n = 20). Molecular analysis of genomic DNA by polymerase chain reaction (PCR) using primers specific for the DMPK gene encompassing the triplet repeat expansion, showed that all controls (n = 20) gave a 2.1 kb band indicating normal triplet repeat number. Three out of 11 cases (two clinically diagnosed DM and one muscular dystrophy) had an expansion of the (CTG)n repeat in the range of 1000-2100 repeats corresponding to the repeat number in cases of severe DM. Other two of these 11 cases, showed a mild expansion of ~ 66 repeats. Three samples, which included two cases of hypotonia and the father of a subject with muscular dystrophy, also gave a similar repeat expansion (~66 repeats). Conclusion: Results suggest a role of (CTG)n expansion at the DMPK locus in unexplained hypotonias and muscular myopathies other than DM. This calls for screening of the triplet repeat expansion at the DMPK locus in cases of idiopathic myopathies and hypotonia. PMID:23560000

  3. Gonosomal mosaicism in myotonic dystrophy patients: Involvement of mitotic events in (CTG)[sub n] repeat variation and selection against extreme expansion in sperm

    SciTech Connect

    Jansen, G.; Coerwinkel, M.; Wieringa, B.; Nillesen, W.; Smeets, H.; Brunner, H.; Wieringa, B. ); Willems, P.; Vits, L. ); Hoeweler, C. )

    1994-04-01

    Myotonic dystrophy (DM) is caused by abnormal expansion of a polymorphic (CTG)[sub n] repeat, located in the DM protein kinase gene. The authors determined the (CTG)[sub n] repeat lengths in a broad range of tissue DNAs from patients with mild, classical, or congenital manifestation of DM. Differences in the repeat length were seen in somatic tissues from single DM individuals and twins. Repeats appeared to expand to a similar extent in tissues originating from the same embryonal origin. In most male patients carrying intermediate- or small-sized expansions in blood, the repeat lengths covered a markedly wider range in sperm. In contrast, male patients with large allele expansions in blood (>700 CTGs) had similar or smaller repeats in sperm, when detectable. Sperm alleles with >1,000 CTGs were not seen. The authors conclude that DM patients can be considered gonosomal mosaics, i.e., combined somatic and germ-line tissue mosaics. Most remarkably, they observed multiple cases where the length distributions of intermediate- or small-sized alleles in fathers' sperm were significantly different from that in their offspring's blood. The combined findings indicate that intergenerational length changes in the unstable CTG repeat are most likely to occur during early embryonic mitotic divisions in both somatic and germ-line tissue formation. Both the initial CTG length, the overall number of cell divisions involved in tissue formation, and perhaps a specific selection process in spermatogenesis may influence the dynamics of this process. A model explaining mitotic instability and sex-dependent segregation phenomena in DM manifestation is discussed. 59 refs., 5 figs.

  4. Influence of sex of the transmitting parent as well as of parental allel size on the CTG expansion in myotonic dystrophy (DM)

    SciTech Connect

    Brunner, H.G.; Brueggenwirth, H.T.; Nillesen, W.; Hamel, B.C.J.; Hoppe, R.L.E.; Oost, B.A. van; Ropers, H.H.; Smeets, H.J.M.; Jansen, G.; Die, C.E.M. de; Hoeweler, C.J. Wieringa, B.

    1993-11-01

    In patients with myotonic dystrophy (DM), the severity of clinical signs is correlated with the length of a (CTG)[sub n] trinucleotide repeat sequence. This sequence tends to expand in subsequent generations. In order to examine the kinetics of this process and, in particular, the influence of the mutant-allele size and the sex of the transmitting parent, the authors have studied (CTG)[sub n] repeat lengths in the offspring of 38 healthy carriers with small mutations (less than 100 CTG trinucleotides, mean length [CTG][sub 67]). In these studies, the authors found a weakly positive correlation between the size of the mutation in the carrier parents and that in their offspring. Furthermore, the authors observed that, in the offspring of male transmitters, repeat lengths exceeding 100 CTG trinucleotides were much more frequent than in the offspring of carrier females (48 [92%] of 52 vs. 7 [44%] of 16, P = .0002). Similarly, in genealogical studies performed in 38 Dutch DM kindreds, an excess of nonmanifesting male transmitters was noted, which was most conspicuous in the generation immediately preceding that with phenotypic expression of DM. Thus, two separate lines of evidence suggest that the sex of the transmitting parent is an important factor that determines DM allele size in the offspring. On the basis of the data, the authors estimate that when both parents are asymptomatic, the odds are approximately 2:1 that the father carries the DM mutation. Because expansion of the CTG repeat is more rapid with male transmission, negative selection during spermatogenesis may be required to explain the exclusive maternal inheritance of severe congenital onset DM. 42 refs., 1 fig., 2 tabs.

  5. Congenital Corneal Endothelial Dystrophies Resulting from Novel De Novo Mutations

    PubMed Central

    Cunnusamy, Khrishen; Bowman, Charles B.; Beebe, Walter; Gong, Xin; Hogan, R. Nick; Mootha, V. Vinod

    2015-01-01

    Purpose To describe two cases of congenital corneal endothelial edema resulting from novel de novo mutations. Methods Case A patient was a 15 months old Caucasian infant and Case B patient was a 3 year old Hispanic child presenting with bilateral cloudy corneas since birth. Clinicopathological findings are presented. DNA samples were screened for mutations in candidate genes by Sanger sequencing. Results Slit-lamp examination of Case A patient revealed stromal edema and haze. Histology of keratoplasty button showed stromal thickening with loss of endothelium and thin Descemet’s membrane. Sanger sequencing established the diagnosis of congenital hereditary endothelial dystrophy (CHED) by detection of a compound heterozygous mutation in SLC4A11. The proband displayed a novel de novo frameshift mutation in one SLC4A11 allele, p.(Pro817Argfs*32), in conjunction with a maternally inherited missense mutation in SLC4A11, p.(Arg869His). Case B patient similarly presented with stromal edema and stromal haze. Histopathological analysis revealed a spongy epithelium, focal discontinuities in Bowman’s layer, stromal thickening with areas of compacted posterior stroma, variable thickness of Descemet’s membrane, and regional multilayered endothelium. Sanger sequencing found a novel de novo nonsense mutation in the first exon of ZEB1, p.(Cys7*). Conclusions To our knowledge, we present the earliest clinical presentation of posterior polymorphous corneal dystrophy resulting from a de novo mutation in ZEB1. Additionally, we present a CHED case with a thin Descemet’s membrane with a novel compound heterozygous SLC4A11 mutation. In the absence of a family history or consanguinity, de novo mutations may result in congenital corneal endothelial dystrophies. PMID:26619383

  6. Length-dependent CTG·CAG triplet-repeat expansion in myotonic dystrophy patient-derived induced pluripotent stem cells

    PubMed Central

    Du, Jintang; Campau, Erica; Soragni, Elisabetta; Jespersen, Christine; Gottesfeld, Joel M.

    2013-01-01

    Myotonic dystrophy type 1 (DM1) is an inherited dominant muscular dystrophy caused by expanded CTG·CAG triplet repeats in the 3′ untranslated region of the DMPK1 gene, which produces a toxic gain-of-function CUG RNA. It has been shown that the severity of disease symptoms, age of onset and progression are related to the length of the triplet repeats. However, the mechanism(s) of CTG·CAG triplet-repeat instability is not fully understood. Herein, induced pluripotent stem cells (iPSCs) were generated from DM1 and Huntington's disease patient fibroblasts. We isolated 41 iPSC clones from DM1 fibroblasts, all showing different CTG·CAG repeat lengths, thus demonstrating somatic instability within the initial fibroblast population. During propagation of the iPSCs, the repeats expanded in a manner analogous to the expansion seen in somatic cells from DM1 patients. The correlation between repeat length and expansion rate identified the interval between 57 and 126 repeats as being an important length threshold where expansion rates dramatically increased. Moreover, longer repeats showed faster triplet-repeat expansion. However, the overall tendency of triplet repeats to expand ceased on differentiation into differentiated embryoid body or neurospheres. The mismatch repair components MSH2, MSH3 and MSH6 were highly expressed in iPSCs compared with fibroblasts, and only occupied the DMPK1 gene harboring longer CTG·CAG triplet repeats. In addition, shRNA silencing of MSH2 impeded CTG·CAG triplet-repeat expansion. The information gained from these studies provides new insight into a general mechanism of triplet-repeat expansion in iPSCs. PMID:23933738

  7. Comparison of temporal and stride characteristics in myotonic dystrophies type 1 and 2 during dual-task walking.

    PubMed

    Radovanović, S; Perić, S; Savić-Pavićević, D; Dobričić, V; Pešović, J; Kostić, V; Rakočević-Stojanović, V

    2016-02-01

    We analyzed temporal and stride characteristics in patients with myotonic dystrophy type 1 (DM1) and type 2 (DM2) while performing dual mental and motor tasks, and investigated correlations between gait parameters and cognitive impairments. Dual-task walking was performed by 37 patients (20 DM1 and 17 DM2) and 48 healthy subjects divided into two groups, age- and gender-matched control group for DM1 (HC1) and age- and gender-matched control group for DM2 (HC2). The subjects performed a basic walking task, dual-motor task, dual-mental task, and combined motor and mental task. DM1 and DM2 patients differed significantly in temporal and stride characteristics compared to HC. Main differences in DM1 were slower gait and shorter stride length, while both DM1 and DM2 patients had a higher degree of variation of the swing time during dual-task gait, a parameter that reflects posture and balance. Impact of the cognitive dual task on gait pattern changes was also observed. Visuospatial ability correlated with gait changes in DM1, while executive functions had stronger influence in DM2 (p<0.01). Both patient groups had leg muscle weakness. Gait pattern was impaired in both patient groups concerning temporal and stride characteristics. Dual-task walking paradigm may discover mild initial gait changes and could provide early identification of fall risks and predict possible falls in DM patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. RBFOX1 Cooperates with MBNL1 to Control Splicing in Muscle, Including Events Altered in Myotonic Dystrophy Type 1

    PubMed Central

    Klinck, Roscoe; Fourrier, Angélique; Thibault, Philippe; Toutant, Johanne; Durand, Mathieu; Lapointe, Elvy; Caillet-Boudin, Marie-Laure; Sergeant, Nicolas; Gourdon, Geneviève; Meola, Giovanni; Furling, Denis; Puymirat, Jack; Chabot, Benoit

    2014-01-01

    With the goal of identifying splicing alterations in myotonic dystrophy 1 (DM1) tissues that may yield insights into targets or mechanisms, we have surveyed mis-splicing events in three systems using a RT-PCR screening and validation platform. First, a transgenic mouse model expressing CUG-repeats identified splicing alterations shared with other mouse models of DM1. Second, using cell cultures from human embryonic muscle, we noted that DM1-associated splicing alterations were significantly enriched in cytoskeleton (e.g. SORBS1, TACC2, TTN, ACTN1 and DMD) and channel (e.g. KCND3 and TRPM4) genes. Third, of the splicing alterations occurring in adult DM1 tissues, one produced a dominant negative variant of the splicing regulator RBFOX1. Notably, half of the splicing events controlled by MBNL1 were co-regulated by RBFOX1, and several events in this category were mis-spliced in DM1 tissues. Our results suggest that reduced RBFOX1 activity in DM1 tissues may amplify several of the splicing alterations caused by the deficiency in MBNL1. PMID:25211016

  9. Myotonic dystrophy type 1 patient-derived iPSCs for the investigation of CTG repeat instability

    PubMed Central

    Ueki, Junko; Nakamori, Masayuki; Nakamura, Masahiro; Nishikawa, Misato; Yoshida, Yoshinori; Tanaka, Azusa; Morizane, Asuka; Kamon, Masayoshi; Araki, Toshiyuki; Takahashi, Masanori P.; Watanabe, Akira; Inagaki, Nobuya; Sakurai, Hidetoshi

    2017-01-01

    Myotonic dystrophy type 1 (DM1) is an autosomal-dominant multi-system disease caused by expanded CTG repeats in dystrophia myotonica protein kinase (DMPK). The expanded CTG repeats are unstable and can increase the length of the gene with age, which worsens the symptoms. In order to establish a human stem cell system suitable for the investigation of repeat instability, DM1 patient-derived iPSCs were generated and differentiated into three cell types commonly affected in DM1, namely cardiomyocytes, neurons and myocytes. Then we precisely analysed the CTG repeat lengths in these cells. Our DM1-iPSCs showed a gradual lengthening of CTG repeats with unchanged repeat distribution in all cell lines depending on the passage numbers of undifferentiated cells. However, the average CTG repeat length did not change significantly after differentiation into different somatic cell types. We also evaluated the chromatin accessibility in DM1-iPSCs using ATAC-seq. The chromatin status in DM1 cardiomyocytes was closed at the DMPK locus as well as at SIX5 and its promoter region, whereas it was open in control, suggesting that the epigenetic modifications may be related to the CTG repeat expansion in DM1. These findings may help clarify the role of repeat instability in the CTG repeat expansion in DM1. PMID:28211918

  10. Muscleblind-like 3 deficit results in a spectrum of age-associated pathologies observed in myotonic dystrophy

    PubMed Central

    Choi, Jongkyu; Dixon, Donald M.; Dansithong, Warunee; Abdallah, Walid F.; Roos, Kenneth P.; Jordan, Maria C.; Trac, Brandon; Lee, Han Shin; Comai, Lucio; Reddy, Sita

    2016-01-01

    Myotonic dystrophy type I (DM1) exhibits distinctive disease specific phenotypes and the accelerated onset of a spectrum of age-associated pathologies. In DM1, dominant effects of expanded CUG repeats result in part from the inactivation of the muscleblind-like (MBNL) proteins. To test the role of MBNL3, we deleted Mbnl3 exon 2 (Mbnl3ΔE2) in mice and examined the onset of age-associated diseases over 4 to 13 months of age. Accelerated onset of glucose intolerance with elevated insulin levels, cardiac systole deficits, left ventricle hypertrophy, a predictor of a later onset of heart failure and the development of subcapsular and cortical cataracts is observed in Mbnl3ΔE2 mice. Retention of embryonic splice isoforms in adult organs, a prominent defect in DM1, is not observed in multiple RNAs including the Insulin Receptor (Insr), Cardiac Troponin T (Tnnt2), Lim Domain Binding 3 (Ldb3) RNAs in Mbnl3ΔE2 mice. Although rare DM1-like splice errors underlying the observed phenotypes cannot be excluded, our data in conjunction with the reported absence of alternative splice errors in embryonic muscles of a similar Mbnl3ΔE2 mouse by RNA-seq studies, suggest that mechanisms distinct from the adult retention of embryonic splice patterns may make important contributions to the onset of age-associated pathologies in DM1. PMID:27484195

  11. Gait pattern in myotonic dystrophy (Steinert disease): a kinematic, kinetic and EMG evaluation using 3D gait analysis.

    PubMed

    Galli, Manuela; Cimolin, Veronica; Crugnola, Veronica; Priano, Lorenzo; Menegoni, Francesco; Trotti, Claudio; Milano, Eva; Mauro, Alessandro

    2012-03-15

    We investigated the gait pattern of 10 patients with myotonic dystrophy (Steinert disease; 4 females, 6 males; age: 41.5+7.6 years), compared to 20 healthy controls, through manual muscle test and gait analysis, in terms of kinematic, kinetic and EMG data. In most of patients (80%) distal muscle groups were weaker than proximal ones. Weakness at lower limbs was in general moderate to severe and MRC values evidenced a significant correlation between tibialis anterior and gastrocnemius medialis (R=0.91). An overall observation of gait pattern in patients when compared to controls showed that most spatio-temporal parameters (velocity, step length and cadence) were significantly different. As concerns kinematics, patients' pelvic tilt was globally in a higher position than control group, with reduced hip extension ability in stance phase and limited range of motion; 60% of the limbs revealed knee hyperextension during midstance and ankle joints showed a quite physiological position at initial contact and higher dorsiflexion during stance phase if compared to healthy individuals. Kinetic plots evidenced higher hip power during loading response and lower ankle power generation in terminal stance. The main EMG abnormalities were seen in tibialis anterior and gastrocnemius medialis muscles. In this study gait analysis gives objective and quantitative information about the gait pattern and the deviations due to the muscular situation of these patients; these results are important from a clinical point of view and suggest that rehabilitation programs for them should take these findings into account.

  12. BNA(NC) Gapmers Revert Splicing and Reduce RNA Foci with Low Toxicity in Myotonic Dystrophy Cells.

    PubMed

    Manning, Kassie S; Rao, Ashish N; Castro, Miguel; Cooper, Thomas A

    2017-09-05

    Myotonic dystrophy type 1 (DM1) is a multisystemic disease caused by an expanded CTG repeat in the 3' UTR of the dystrophia myotonica protein kinase (DMPK) gene. Short, DNA-based antisense oligonucleotides termed gapmers are a promising strategy to degrade toxic CUG expanded repeat (CUGexp) RNA. Nucleoside analogs are incorporated to increase gapmer affinity and stability; however, some analogs also exhibit toxicity. In this study, we demonstrate that the 2',4'-BNA(NC)[NMe] (BNA(NC)) modification is a promising nucleoside analog with high potency similar to 2',4'-LNA (LNA). BNA(NC) gapmers targeting a nonrepetitive region of the DMPK 3' UTR show allele-specific knockdown of CUGexp RNA and revert characteristic DM1 molecular defects including mis-splicing and accumulation of RNA foci. Notably, the BNA(NC) gapmers tested in this study did not induce caspase activation, in contrast to a sequence matched LNA gapmer. This study indicates that BNA(NC) gapmers warrant further study as a promising RNA targeting therapeutic.

  13. Triplet Repeat–Derived siRNAs Enhance RNA–Mediated Toxicity in a Drosophila Model for Myotonic Dystrophy

    PubMed Central

    Yu, Zhenming; Teng, Xiuyin; Bonini, Nancy M.

    2011-01-01

    More than 20 human neurological and neurodegenerative diseases are caused by simple DNA repeat expansions; among these, non-coding CTG repeat expansions are the basis of myotonic dystrophy (DM1). Recent work, however, has also revealed that many human genes have anti-sense transcripts, raising the possibility that human trinucleotide expansion diseases may be comprised of pathogenic activities due both to a sense expanded-repeat transcript and to an anti-sense expanded-repeat transcript. We established a Drosophila model for DM1 and tested the role of interactions between expanded CTG transcripts and expanded CAG repeat transcripts. These studies revealed dramatically enhanced toxicity in flies co-expressing CTG with CAG expanded repeats. Expression of the two transcripts led to novel pathogenesis with the generation of dcr-2 and ago2-dependent 21-nt triplet repeat-derived siRNAs. These small RNAs targeted the expression of CAG-containing genes, such as Ataxin-2 and TATA binding protein (TBP), which bear long CAG repeats in both fly and man. These findings indicate that the generation of triplet repeat-derived siRNAs may dramatically enhance toxicity in human repeat expansion diseases in which anti-sense transcription occurs. PMID:21437269

  14. Simple Repeat-Primed PCR Analysis of the Myotonic Dystrophy Type 1 Gene in a Clinical Diagnostics Environment

    PubMed Central

    Dryland, Philippa A.; Doherty, Elaine; Love, Jennifer M.; Love, Donald R.

    2013-01-01

    Myotonic dystrophy type 1 is an autosomal dominant neuromuscular disorder that is caused by the expansion of a CTG trinucleotide repeat in the DMPK gene. The confirmation of a clinical diagnosis of DM-1 usually involves PCR amplification of the CTG repeat-containing region and subsequent sizing of the amplification products in order to deduce the number of CTG repeats. In the case of repeat hyperexpansions, Southern blotting is also used; however, the latter has largely been superseded by triplet repeat-primed PCR (TP-PCR), which does not yield a CTG repeat number but nevertheless provides a means of stratifying patients regarding their disease severity. We report here a combination of forward and reverse TP-PCR primers that allows for the simple and effective scoring of both the size of smaller alleles and the presence or absence of expanded repeat sequences. In addition, the CTG repeat-containing TP-PCR forward primer can target both the DM-1 and Huntington disease genes, thereby streamlining the work flow for confirmation of clinical diagnoses in a diagnostic laboratory. PMID:26317000

  15. Genome Therapy of Myotonic Dystrophy Type 1 iPS Cells for Development of Autologous Stem Cell Therapy.

    PubMed

    Gao, Yuanzheng; Guo, Xiuming; Santostefano, Katherine; Wang, Yanlin; Reid, Tammy; Zeng, Desmond; Terada, Naohiro; Ashizawa, Tetsuo; Xia, Guangbin

    2016-08-01

    Myotonic dystrophy type 1 (DM1) is caused by expanded Cytosine-Thymine-Guanine (CTG) repeats in the 3'-untranslated region (3' UTR) of the Dystrophia myotonica protein kinase (DMPK) gene, for which there is no effective therapy. The objective of this study is to develop genome therapy in human DM1 induced pluripotent stem (iPS) cells to eliminate mutant transcripts and reverse the phenotypes for developing autologous stem cell therapy. The general approach involves targeted insertion of polyA signals (PASs) upstream of DMPK CTG repeats, which will lead to premature termination of transcription and elimination of toxic mutant transcripts. Insertion of PASs was mediated by homologous recombination triggered by site-specific transcription activator-like effector nuclease (TALEN)-induced double-strand break. We found genome-treated DM1 iPS cells continue to maintain pluripotency. The insertion of PASs led to elimination of mutant transcripts and complete disappearance of nuclear RNA foci and reversal of aberrant splicing in linear-differentiated neural stem cells, cardiomyocytes, and teratoma tissues. In conclusion, genome therapy by insertion of PASs upstream of the expanded DMPK CTG repeats prevented the production of toxic mutant transcripts and reversal of phenotypes in DM1 iPS cells and their progeny. These genetically-treated iPS cells will have broad clinical application in developing autologous stem cell therapy for DM1.

  16. Induction and Reversal of Myotonic Dystrophy Type 1 Pre-mRNA Splicing Defects by Small Molecules

    PubMed Central

    Childs-Disney, Jessica L.; Stepniak-Konieczna, Ewa; Tran, Tuan; Yildirim, Ilyas; Park, HaJeung; Chen, Catherine Z.; Hoskins, Jason; Southall, Noel; Marugan, Juan J.; Patnaik, Samarjit; Zheng, Wei; Austin, Chris P.; Schatz, George C.; Sobczak, Krzysztof; Thornton, Charles A.; Disney, Matthew D.

    2013-01-01

    The ability to control pre-mRNA splicing with small molecules could facilitate the development of therapeutics or cell-based circuits that control gene function. Myotonic dystrophy type 1 (DM1) is caused by the dysregulation of alternative pre-mRNA splicing due to sequestration of muscleblind-like 1 protein (MBNL1) by expanded, non-coding r(CUG) repeats (r(CUG)exp). Here we report two small molecules that induce or ameliorate alternative splicing dysregulation. The thiophene-containing small molecule (1) inhibits the interaction of MBNL1 with its natural pre-mRNA substrates. Compound (2), a substituted naphthyridine, binds r(CUG)exp and displaces MBNL1. Structural models show that 1 binds MBNL1 in the Zn-finger domain and that 2 interacts with UU loops in r(CUG)exp. This study provides a structural framework for small molecules that target MBNL1 by mimicking r(CUG)exp and shows that targeting MBNL1 causes dysregulation of alternative splicing, suggesting that MBNL1 is thus not a suitable therapeutic target for the treatment of DM1. PMID:23806903

  17. Abnormal sodium current properties contribute to cardiac electrical and contractile dysfunction in a mouse model of myotonic dystrophy type 1.

    PubMed

    Algalarrondo, Vincent; Wahbi, Karim; Sebag, Frédéric; Gourdon, Geneviève; Beldjord, Chérif; Azibi, Kamel; Balse, Elise; Coulombe, Alain; Fischmeister, Rodolphe; Eymard, Bruno; Duboc, Denis; Hatem, Stéphane N

    2015-04-01

    Myotonic dystrophy type 1 (DM1) is the most common neuromuscular disorder and is associated with cardiac conduction defects. However, the mechanisms of cardiac arrhythmias in DM1 are unknown. We tested the hypothesis that abnormalities in the cardiac sodium current (INa) are involved, and used a transgenic mouse model reproducing the expression of triplet expansion observed in DM1 (DMSXL mouse). The injection of the class-I antiarrhythmic agent flecainide induced prominent conduction abnormalities and significantly lowered the radial tissular velocities and strain rate in DMSXL mice compared to WT. These abnormalities were more pronounced in 8-month-old mice than in 3-month-old mice. Ventricular action potentials recorded by standard glass microelectrode technique exhibited a lower maximum upstroke velocity [dV/dt](max) in DMSXL. This decreased [dV/dt](max) was associated with a 1.7 fold faster inactivation of INa in DMSXL myocytes measured by the whole-cell patch-clamp technique. Finally in the DMSXL mouse, no mutation in the Scn5a gene was detected and neither cardiac fibrosis nor abnormalities of expression of the sodium channel protein were observed. Therefore, alterations in the sodium current markedly contributed to electrical conduction block in DM1. This result should guide pharmaceutical and clinical research toward better therapy for the cardiac arrhythmias associated with DM1.

  18. Brain MRI abnormalities in the adult form of myotonic dystrophy type 1: A longitudinal case series study.

    PubMed

    Conforti, Renata; de Cristofaro, Mario; Cristofano, Adriana; Brogna, Barbara; Sardaro, Angela; Tedeschi, Gioacchino; Cirillo, Sossio; Di Costanzo, Alfonso

    2016-02-01

    This study aimed to verify whether brain abnormalities, previously described in patients with myotonic dystrophy type 1 (DM1) by magnetic resonance imaging (MRI), progressed over time and, if so, to characterize their progression. Thirteen DM1 patients, who had at least two MRI examinations, were retrospectively evaluated and included in the study. The mean duration (± standard deviation) of follow-up was 13.4 (±3.8) years, over a range of 7-20 years. White matter lesions (WMLs) were rated by semi-quantitative method, the signal intensity of white matter poster-superior to trigones (WMPST) by reference to standard images and brain atrophy by ventricular/brain ratio (VBR). At the end of MRI follow-up, the scores relative to lobar, temporal and periventricular WMLs, to WMPST signal intensity and to VBR were significantly increased compared to baseline, and MRI changes were more evident in some families than in others. No correlation was found between the MRI changes and age, onset, disease duration, muscular involvement, CTG repetition and follow-up duration. These results demonstrated that white matter involvement and brain atrophy were progressive in DM1 and suggested that progression rate varied from patient to patient, regardless of age, disease duration and genetic defect.

  19. Reliable and versatile immortal muscle cell models from healthy and myotonic dystrophy type 1 primary human myoblasts.

    PubMed

    Pantic, Boris; Borgia, Doriana; Giunco, Silvia; Malena, Adriana; Kiyono, Tohru; Salvatori, Sergio; De Rossi, Anita; Giardina, Emiliano; Sangiuolo, Federica; Pegoraro, Elena; Vergani, Lodovica; Botta, Annalisa

    2016-03-01

    Primary human skeletal muscle cells (hSkMCs) are invaluable tools for deciphering the basic molecular mechanisms of muscle-related biological processes and pathological alterations. Nevertheless, their use is quite restricted due to poor availability, short life span and variable purity of the cells during in vitro culture. Here, we evaluate a recently published method of hSkMCs immortalization, relying on ectopic expression of cyclin D1 (CCND1), cyclin-dependent kinase 4 (CDK4) and telomerase (TERT) in myoblasts from healthy donors (n=3) and myotonic dystrophy type 1 (DM1) patients (n=2). The efficacy to maintain the myogenic and non-transformed phenotype, as well as the main pathogenetic hallmarks of DM1, has been assessed. Combined expression of the three genes i) maintained the CD56(NCAM)-positive myoblast population and differentiation potential; ii) preserved the non-transformed phenotype and iii) maintained the CTG repeat length, amount of nuclear foci and aberrant alternative splicing in immortal muscle cells. Moreover, immortal hSkMCs displayed attractive additional features such as structural maturation of sarcomeres, persistence of Pax7-positive cells during differentiation and complete disappearance of nuclear foci following (CAG)7 antisense oligonucleotide (ASO) treatment. Overall, the CCND1, CDK4 and TERT immortalization yields versatile, reliable and extremely useful human muscle cell models to investigate the basic molecular features of human muscle cell biology, to elucidate the molecular pathogenetic mechanisms and to test new therapeutic approaches for DM1 in vitro.

  20. Respiratory failure in a mouse model of myotonic dystrophy does not correlate with the CTG repeat length.

    PubMed

    Panaite, Petrica-Adrian; Kuntzer, Thierry; Gourdon, Geneviève; Barakat-Walter, Ibtissam

    2013-10-01

    Myotonic dystrophy (DM1) is a multisystemic disease caused by an expansion of CTG repeats in the region of DMPK, the gene encoding DM protein kinase. The severity of muscle disability in DM1 correlates with the size of CTG expansion. As respiratory failure is one of the main causes of death in DM1, we investigated the correlation between respiratory impairment and size of the (CTG)n repeat in DM1 animal models. Using pressure plethysmography the respiratory function was assessed in control and transgenic mice carrying either 600 (DM600) or >1300 CTG repeats (DMSXL). The statistical analysis of respiratory parameters revealed that both DM1 transgenic mice sub-lines show respiratory impairment compared to control mice. In addition, there is no significant difference in breathing functions between the DM600 and DMSXL mice. In conclusion, these results indicate that respiratory impairment is present in both transgenic mice sub-lines, but the severity of respiratory failure is not related to the size of the (CTG)n expansion.

  1. Far field R-wave sensing in Myotonic Dystrophy type 1: right atrial appendage versus Bachmann's bundle region lead placement.

    PubMed

    Russo, Vincenzo; Nigro, Gerardo; Antonio Papa, Andrea; Rago, Anna; Di Meo, Federica; Cristiano, Anna; Molino, Antonio; Calabrò, Raffaele; Giovanna Russo, Maria; Politano, Luisa

    2014-10-01

    Aim of the present study was to investigate far field R-wave sensing (FFRS) timing and characteristics in 34 Myotonic Dystrophy type 1 (DM1) patients undergoing dual chamber pacemaker implantation, comparing Bachmann's bundle (BB) stimulation (16 patients) site with the conventional right atrial appendage (RAA) pacing site (18 patients). All measurements were done during sinus rhythm and in supine position, with unipolar (UP) and bipolar (BP) sensing configuration. The presence, amplitude threshold (FFRS trsh) and FFRS timing were determined. There were no differences between both atrial sites in the Pmin and Pmean values of sensed P-wave amplitudes, as well as between UP and BP sensing configurations. The FFRS trsh was lower at the BB region in comparison to the RAA site. The mean BP FFRS trsh was significantly lower than UP configuration in both atrial locations. There were no significant differences in atrial pacing threshold, sensing threshold and atrial lead impedances at the implant time and at FFRS measurements. Bachmann's bundle area is an optimal atrial lead position for signal sensing as well as conventional RAA, but it offers the advantage of reducing the oversensing of R-wave on the atrial lead, thus improving functioning of standard dual chamber pacemakers in DM1 patients.

  2. Saccharomyces cerevisiae Gis2 interacts with the translation machinery and is orthogonal to myotonic dystrophy type 2 protein ZNF9.

    PubMed

    Sammons, Morgan A; Samir, Parimal; Link, Andrew J

    2011-03-04

    The myotonic dystrophy type 2 protein ZNF9/CNBP is a small nucleic acid binding protein proposed to act as a regulator of transcription and translation. The precise functions and activity of this protein are poorly understood. Previous studies suggested that ZNF9 regulates translation and facilitates the process of cap-independent translation through interactions with mRNA and the translating ribosome. To help determine the role played by ZNF9 in the activation of translation initiation, we combined genetic and biochemical analysis of the putative ZNF9 ortholog GIS2, in the budding yeast Saccharomyces cerevisiae. Purification of the Gis2p protein followed by mass spectrometry based-proteomic analysis identified a large number of co-purifying ribosomal subunits and translation factors, strongly suggesting that Gis2p interacts with the protein translation machinery. Polysome profiling and ribosome isolation experiments confirm that Gis2p physically interacts with the translating ribosome. Interestingly, expression of yeast Gis2p in HEK293T cells activates cap-independent translation driven by the 5'UTR of the ODC gene. These data suggest that Gis2 is functionally orthologous to ZNF9 and acts as a cap-independent translation factor.

  3. Development of pharmacophore models for small molecules targeting RNA: Application to the RNA repeat expansion in myotonic dystrophy type 1.

    PubMed

    Angelbello, Alicia J; González, Àlex L; Rzuczek, Suzanne G; Disney, Matthew D

    2016-12-01

    RNA is an important drug target, but current approaches to identify bioactive small molecules have been engineered primarily for protein targets. Moreover, the identification of small molecules that bind a specific RNA target with sufficient potency remains a challenge. Computer-aided drug design (CADD) and, in particular, ligand-based drug design provide a myriad of tools to identify rapidly new chemical entities for modulating a target based on previous knowledge of active compounds without relying on a ligand complex. Herein we describe pharmacophore virtual screening based on previously reported active molecules that target the toxic RNA that causes myotonic dystrophy type 1 (DM1). DM1-associated defects are caused by sequestration of muscleblind-like 1 protein (MBNL1), an alternative splicing regulator, by expanded CUG repeats (r(CUG)(exp)). Several small molecules have been found to disrupt the MBNL1-r(CUG)(exp) complex, ameliorating DM1 defects. Our pharmacophore model identified a number of potential lead compounds from which we selected 11 compounds to evaluate. Of the 11 compounds, several improved DM1 defects both in vitro and in cells.

  4. Serum response factor regulates smooth muscle contractility via myotonic dystrophy protein kinases and L-type calcium channels

    PubMed Central

    Lee, Moon Young; Park, Chanjae; Ha, Se Eun; Park, Paul J.; Berent, Robyn M.; Jorgensen, Brian G.; Corrigan, Robert D.; Grainger, Nathan; Blair, Peter J.; Slivano, Orazio J.; Miano, Joseph M.; Ward, Sean M.; Smith, Terence K.; Sanders, Kenton M.

    2017-01-01

    Serum response factor (SRF) transcriptionally regulates expression of contractile genes in smooth muscle cells (SMC). Lack or decrease of SRF is directly linked to a phenotypic change of SMC, leading to hypomotility of smooth muscle in the gastrointestinal (GI) tract. However, the molecular mechanism behind SRF-induced hypomotility in GI smooth muscle is largely unknown. We describe here how SRF plays a functional role in the regulation of the SMC contractility via myotonic dystrophy protein kinase (DMPK) and L-type calcium channel CACNA1C. GI SMC expressed Dmpk and Cacna1c genes into multiple alternative transcriptional isoforms. Deficiency of SRF in SMC of Srf knockout (KO) mice led to reduction of SRF-dependent DMPK, which down-regulated the expression of CACNA1C. Reduction of CACNA1C in KO SMC not only decreased intracellular Ca2+ spikes but also disrupted their coupling between cells resulting in decreased contractility. The role of SRF in the regulation of SMC phenotype and function provides new insight into how SMC lose their contractility leading to hypomotility in pathophysiological conditions within the GI tract. PMID:28152551

  5. Motor unit reorganization in progressive muscular dystrophies and congenital myopathies.

    PubMed

    Szmidt-Sałkowska, Elżbieta; Gaweł, Małgorzata; Lipowska, Marta

    2015-01-01

    The aim of this study was to analyze motor unit reorganization in different types of progressive muscular dystrophies and congenital myopathies. The study population consisted of patients with genetically verified progressive muscular dystrophies: Duchenne (DMD) (n=54), Becker (BMD) (n=30), facio-scapulo-humeral (FSHD) (n=37), and Emery-Dreifuss (E-DD) (n=26). Patients with probable limb-girdle dystrophy (L-GD) (n=58) and congenital myopathies (n=35) were also included in the study. Quantitative EMG recordings were obtained from 469 muscles. Muscle activity at rest and during slight voluntary and maximal muscle contraction was analyzed. The motor unit activity potential (MUAP) duration, amplitude, area, size index (SI), polyphasicity, and the presence of "outliers" were evaluated. Diminished values of MUAP parameters and decreased maximal amplitude of maximal muscle contraction were recorded most frequently in DMD and mainly in the biceps brachii muscles. SI was the most frequently changed EMG parameter. "Outliers" with amplitude below the normal range were recorded more frequently then a decreased mean MUAP amplitude (what could indicate a very high sensitivity of this EMG parameter). Pathological interference pattern was recorded in 34.7% of biceps brachii and in 21.2% of rectus femoris muscles. In FSHD, decreased MUAP duration and SI and pathological interference pattern with low amplitude were recorded most frequently in the tibial anterior and deltoid muscles. The presence of potentials with reduced parameters is a result of decreasing motor unit area (reduced number and size of muscle fibers), while high amplitude potentials recorded in BMD and E-DD could indicate a slow and mild course of disease and muscle regeneration.

  6. NMR spectroscopy and molecular dynamics simulation of r(CCGCUGCGG)₂ reveal a dynamic UU internal loop found in myotonic dystrophy type 1.

    PubMed

    Parkesh, Raman; Fountain, Matthew; Disney, Matthew D

    2011-02-08

    The NMR structure of an RNA with a copy of the 5'CUG/3'GUC motif found in the triplet repeating disorder myotonic dystrophy type 1 (DM1) is disclosed. The lowest energy conformation of the UU pair is a single-hydrogen bond structure; however, the UU protons undergo exchange indicating structural dynamics. Molecular dynamics simulations show that the single hydrogen bond structure is the most populated one but the UU pair interconverts among zero, one, and two hydrogen bond pairs. These studies have implications for the recognition of the DM1 RNA by small molecules and proteins.

  7. [Rapid sequence induction in a patient with Steinert myotonic dystrophy: Interest of the association of high doses of rocuronium and sugammadex].

    PubMed

    Pellegrini, L; Mercier, M-F; Cornese, A; Blasco, V; Albanèse, J

    2012-02-01

    We report in this clinical case the successful use of a combination of rocuronium and sugammadex in a patient with Steinert myotonic dystrophy to perform a rapid sequence induction of anaesthesia. The patient had both contraindication to succinylcholine and a risk of prolonged neuromuscular blockade with non-depolarizing neuromuscular blocking agents. The use of high dose rocuronium (1mg/kg) allowed a quick and easy orotracheal intubation but induced a prolonged neuromuscular block, reversed with success by sugammadex (8 mg/kg).

  8. Congenital muscular dystrophy type 1A with residual merosin expression.

    PubMed

    Kim, Hyo Jeong; Choi, Young-Chul; Park, Hyung Jun; Lee, Young-Mock; Kim, Heung Dong; Lee, Joon Soo; Kang, Hoon-Chul

    2014-03-01

    Congenital muscular dystrophy type 1A (MDC1A) is an autosomal recessive disorder characterized by hypotonia, elevated serum creatine kinase level, delayed motor milestones, white matter changes observed by brain magnetic resonance imaging, and normal intelligence. A mutation in the laminin α2 (LAMA2) gene, located at 6q22-23, is a genetic cause of MDC1A. Patients have merosin (laminin α2)-deficient skeletal muscles. However, the degree of merosin expression ranges from total absence to partial reduction. Patients with residual merosin expression have more variable and milder phenotypes than those with absolute merosin deficiency. We observed a Korean girl with MDC1A with residual merosin expression. Clinical presentation of this patient was typical except for late onset of the disease and external capsule involvement. Immunohistochemical staining of muscle fibers including merosin, is important to evaluate patients with hypotonia, delayed motor development, and abnormal white matter changes.

  9. [Potential of the zebrafish model to study congenital muscular dystrophies].

    PubMed

    Ryckebüsch, Lucile

    2015-10-01

    In order to better understand the complexity of congenital muscular dystrophies (CMD) and develop new strategies to cure them, it is important to establish new disease models. Due to its numerous helpful attributes, the zebrafish has recently become a very powerful animal model for the study of CMD. For some CMD, this vertebrate model is phenotypically closer to human pathology than the murine model. Over the last few years, researchers have developed innovative techniques to screen rapidly and on a large scale for muscle defects in zebrafish. Furthermore, new genome editing techniques in zebrafish make possible the identification of new disease models. In this review, the major attributes of zebrafish for CMD studies are discussed and the principal models of CMD in zebrafish are highlighted.

  10. MKBP, a Novel Member of the Small Heat Shock Protein Family, Binds and Activates the Myotonic Dystrophy Protein Kinase

    PubMed Central

    Suzuki, Atsushi; Sugiyama, Yuki; Hayashi, Yukiko; Nyu-i, Nobuo; Yoshida, Michihiko; Nonaka, Ikuya; Ishiura, Sho-ichi; Arahata, Kiichi; Ohno, Shigeo

    1998-01-01

    Muscle cells are frequently subjected to severe conditions caused by heat, oxidative, and mechanical stresses. The small heat shock proteins (sHSPs) such as αB-crystallin and HSP27, which are highly expressed in muscle cells, have been suggested to play roles in maintaining myofibrillar integrity against such stresses. Here, we identified a novel member of the sHSP family that associates specifically with myotonic dystrophy protein kinase (DMPK). This DMPK-binding protein, MKBP, shows a unique nature compared with other known sHSPs: (a) In muscle cytosol, MKBP exists as an oligomeric complex separate from the complex formed by αB-crystallin and HSP27. (b) The expression of MKBP is not induced by heat shock, although it shows the characteristic early response of redistribution to the insoluble fraction like other sHSPs. Immunohistochemical analysis of skeletal muscle cells shows that MKBP localizes to the cross sections of individual myofibrils at the Z-membrane as well as the neuromuscular junction, where DMPK has been suggested to be concentrated. In vitro, MKBP enhances the kinase activity of DMPK and protects it from heat-induced inactivation. These results suggest that MKBP constitutes a novel stress-responsive system independent of other known sHSPs in muscle cells and that DMPK may be involved in this system by being activated by MKBP. Importantly, since the amount of MKBP protein, but not that of other sHSP family member proteins, is selectively upregulated in skeletal muscle from DM patients, an interaction between DMPK and MKBP may be involved in the pathogenesis of DM. PMID:9490724

  11. Muscleblind-like1 undergoes ectopic relocation in the nuclei of skeletal muscles in myotonic dystrophy and sarcopenia.

    PubMed

    Malatesta, M; Giagnacovo, M; Costanzo, M; Cisterna, B; Cardani, R; Meola, G

    2013-04-22

    Muscleblind-like 1 (MBNL1) is an alternative splicing factor involved in postnatal development of skeletal muscles and heart in humans and mice, and its deregulation is known to be pivotal in the onset and development of myotonic dystrophy (DM). In fact, in DM patients this protein is ectopically sequestered into intranuclear foci, thus compromising the regulation of the alternative splicing of several genes. However, despite the numerous biochemical and molecular studies, scarce attention has been paid to the intranuclear location of MBNL1 outside the foci, although previous data demonstrated that in DM patients various splicing and cleavage factors undergo an abnormal intranuclear distribution suggestive of impaired RNA processing. Interestingly, these nuclear alterations strongly remind those observed in sarcopenia i.e., the loss of muscle mass and function which physiologically occurs during ageing. On this basis, in the present investigation the ultrastructural localization of MBNL1 was analyzed in the myonuclei of skeletal muscles from healthy and DM patients as well as from adult and old (sarcopenic) mice, in the attempt to elucidate possible changes in its distribution and amount. Our data demonstrate that in both dystrophic and sarcopenic muscles MBNL1 undergoes intranuclear relocation, accumulating in its usual functional sites but also ectopically moving to domains which are usually devoid of this protein in healthy adults. This accumulation/delocalization could contribute to hamper the functionality of the whole splicing machinery, leading to a lower nuclear metabolic activity and, consequently, to a less efficient protein synthesis. Moreover, the similar nuclear alterations found in DM and sarcopenia may account for the similar muscle tissue features (myofibre atrophy, fibre size variability and centrally located nuclei), and, in general, for the aging-reminiscent phenotype observed in DM patients.

  12. A low absolute number of expanded transcripts is involved in myotonic dystrophy type 1 manifestation in muscle

    PubMed Central

    Gudde, Anke E. E. G.; González-Barriga, Anchel; van den Broek, Walther J. A. A.; Wieringa, Bé; Wansink, Derick G.

    2016-01-01

    Muscular manifestation of myotonic dystrophy type 1 (DM1), a common inheritable degenerative multisystem disorder, is mainly caused by expression of RNA from a (CTG·CAG)n-expanded DM1 locus. Here, we report on comparative profiling of expression of normal and expanded endogenous or transgenic transcripts in skeletal muscle cells and biopsies from DM1 mouse models and patients in order to help us in understanding the role of this RNA-mediated toxicity. In tissue of HSALR mice, the most intensely used ‘muscle-only’ model in the DM1 field, RNA from the α-actin (CTG)250 transgene was at least 1000-fold more abundant than that from the Dmpk gene, or the DMPK gene in humans. Conversely, the DMPK transgene in another line, DM500/DMSXL mice, was expressed ∼10-fold lower than the endogenous gene. Temporal regulation of expanded RNA expression differed between models. Onset of expression occurred remarkably late in HSALR myoblasts during in vitro myogenesis whereas Dmpk or DMPK (trans)genes were expressed throughout proliferation and differentiation phases. Importantly, quantification of absolute transcript numbers revealed that normal and expanded Dmpk/DMPK transcripts in mouse models and DM1 patients are low-abundance RNA species. Northern blotting, reverse transcriptase–quantitative polymerase chain reaction, RNA-sequencing and fluorescent in situ hybridization analyses showed that they occur at an absolute number between one and a few dozen molecules per cell. Our findings refine the current RNA dominance theory for DM1 pathophysiology, as anomalous factor binding to expanded transcripts and formation of soluble or insoluble ribonucleoprotein aggregates must be nucleated by only few expanded DMPK transcripts and therefore be a small numbers game. PMID:26908607

  13. The cognitive profile of myotonic dystrophy type 1: A systematic review and meta-analysis.

    PubMed

    Okkersen, Kees; Buskes, Melanie; Groenewoud, Johannes; Kessels, Roy P C; Knoop, Hans; van Engelen, Baziel; Raaphorst, Joost

    2017-10-01

    To examine the cognitive profile of patients with myotonic dystrophy type 1 (DM1) on the basis of a systematic review and meta-analysis of the literature. Embase, Medline and PsycInfo were searched for studies reporting ≥1 neuropsychological test in both DM1 patients and healthy controls. Search, data extraction and risk of bias analysis were independently performed by two authors to minimize error. Neuropsychological tests were categorized into 12 cognitive domains and effect sizes (Hedges' g) were calculated for each domain and for tests administered in ≥5 studies. DM1 participants demonstrated a significantly worse performance compared to controls in all cognitive domains. Effect sizes ranged from -.33 (small) for verbal memory to -1.01 (large) for visuospatial perception. Except for the domains global cognition, intelligence and social cognition, wide confidence intervals (CIs) were associated with moderate to marked statistical heterogeneity that necessitates careful interpretation of results. Out of the individual tests, the Rey-Osterrieth complex figure-copy (both non-verbal memory and visuoconstruction) showed consistent impairment with acceptable heterogeneity. In DM1 patients, cognitive deficits may include a variable combination of global cognitive impairment with involvement across different domains, including social cognition, memory and visuospatial functioning. Although DM1 is a heterogeneous disorder, our study shows that meta-analysis is feasible, contributes to the understanding of brain involvement and may direct bedside testing. The protocol for this study has been registered in PROSPERO (International prospective register of systematic reviews) under ID: 42016037415. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Premature Senescence in Primary Muscle Cultures of Myotonic Dystrophy Type 2 is not Associated with p16 Induction

    PubMed Central

    Renna, L.V.; Cardani, R.; Botta, A.; Rossi, G.; Fossati, B.; Costa, E.; Meola, G.

    2014-01-01

    Myotonic dystrophy type 1 (DM1) and type 2 (DM2) are multisystemic disorders linked to two different genetic loci and characterized by several features including myotonia, muscle weakness and atrophy, cardiac dysfunctions, cataracts and insulin-resistance. In both forms, expanded nucleotide sequences cause the accumulation of mutant transcripts in the nucleus deregulating the activity of some RNA-binding proteins and providing an explanation for the multisystemic phenotype of DM patients. However this pathogenetic mechanism does not explain some histopathological features of DM skeletal muscle like muscle atrophy. It has been observed that DM muscle shares similarities with the ageing muscle, where the progressive muscle weakness and atrophy is accompanied by a lower regenerative capacity possibly due to the failure in satellite cells activation. The aim of our study is to investigate if DM2 satellite cell derived myoblasts exhibit a premature senescence as reported for DM1 and if alterations in their proliferation potential and differentiation capabilities might contribute to some of the histopathological features observed in DM2 muscles. Our results indicate that DM myoblasts have lower proliferative capability than control myoblasts and reach in vitro senescence earlier than controls. Differentely from DM1, the p16 pathway is not responsible for the premature growth arrest observed in DM2 myoblasts which stop dividing with telomeres shorter than controls. During in vitro senescence, a progressive decrease in fusion index is observable in both DM and control myotubes with no significant differences between groups. Moreover, myotubes obtained from senescent myoblasts appear to be smaller than those from young myoblasts. Taken together, our data indicate a possible role of DM2 premature myoblast senescence in skeletal muscle histopathological alterations i.e., dystrophic changes and type 2 fibre atrophy. PMID:25578974

  15. Activation of the innate immune response and interferon signalling in myotonic dystrophy type 1 and type 2 cataracts.

    PubMed

    Rhodes, Jeremy D; Lott, Martin C; Russell, Sarah L; Moulton, Vincent; Sanderson, Julie; Wormstone, I Michael; Broadway, David C

    2012-02-15

    Myotonic dystrophy (DM) is caused by a triplet repeat expansion in the non-coding region of either the DMPK (DM1) or CNBP (DM2) gene. Transcription of the expanded region causes accumulation of double-stranded RNA (dsRNA) in DM cells. We sought to determine how expression of triplet repeat RNA causes the varied phenotype typical of DM. Global transcription was measured in DM and non-DM cataract samples using Illumina Bead Arrays. DM samples were compared with non-DM samples and lists of differentially expressed genes (P≤ 0.05) were prepared. Gene set enrichment analysis and the Interferome database were used to search for significant patterns of gene expression in DM cells. Expression of individual genes was measured using quantitative real-time polymerase chain reaction. DMPK and CNBP expression was confirmed in native lens cells showing that a toxic RNA gain of function mechanism could exist in lens. A high proportion, 83% in DM1 and 75% in DM2, of the significantly disregulated genes were shared by both forms of the disease, suggesting a common mechanism. The upregulated genes in DM1 and DM2 were highly enriched in both interferon-regulated genes (IRGs) and genes associated with the response to dsRNA and the innate immune response. The characteristic fingerprint of IRGs and the signalling pathways identified in lens cells support a role for dsRNA activation of the innate immune response in the pathology of DM. This new evidence forms the basis for a novel hypothesis to explain the complex mechanism of DM.

  16. Quantifying Cancer Absolute Risk and Cancer Mortality in the Presence of Competing Events after a Myotonic Dystrophy Diagnosis

    PubMed Central

    Gadalla, Shahinaz M.; Pfeiffer, Ruth M.; Kristinsson, Sigurdur Y.; Björkholm, Magnus; Hilbert, James E.; Moxley, Richard T.; Landgren, Ola; Greene, Mark H.

    2013-01-01

    Recent studies show that patients with myotonic dystrophy (DM) have an increased risk of specific malignancies, but estimates of absolute cancer risk accounting for competing events are lacking. Using the Swedish Patient Registry, we identified 1,081 patients with an inpatient and/or outpatient diagnosis of DM between 1987 and 2007. Date and cause of death and date of cancer diagnosis were extracted from the Swedish Cause of Death and Cancer Registries. We calculated non-parametric estimates of absolute cancer risk and cancer mortality accounting for the high non-cancer competing mortality associated with DM. Absolute cancer risk after DM diagnosis was 1.6% (95% CI=0.4-4%), 5% (95% CI=3-9%) and 9% (95% CI=6-13%) at ages 40, 50 and 60 years, respectively. Females had a higher absolute risk of all cancers combined than males: 9% (95% CI=4-14), and 13% (95% CI=9-20) vs. 2% (95%CI= 0.7-6) and 4% (95%CI=2-8) by ages 50 and 60 years, respectively) and developed cancer at younger ages (median age =51 years, range=22-74 vs. 57, range=43-84, respectively, p=0.02). Cancer deaths accounted for 10% of all deaths, with an absolute cancer mortality risk of 2% (95%CI=1-4.5%), 4% (95%CI=2-6%), and 6% (95%CI=4-9%) by ages 50, 60, and 70 years, respectively. No gender difference in cancer-specific mortality was observed (p=0.6). In conclusion, cancer significantly contributes to morbidity and mortality in DM patients, even after accounting for high competing DM mortality from non-neoplastic causes. It is important to apply population-appropriate, validated cancer screening strategies in DM patients. PMID:24236163

  17. Studying a Drug-like, RNA-Focused Small Molecule Library Identifies Compounds That Inhibit RNA Toxicity in Myotonic Dystrophy

    PubMed Central

    Rzuczek, Suzanne G.; Southern, Mark R.; Disney, Matthew D.

    2016-01-01

    There are many RNA targets in the transcriptome to which small molecule chemical probes and lead therapeutics are desired. However, identifying compounds that bind and modulate RNA function in cellulo is difficult. Although rational design approaches have been developed, they are still in their infancies and leave many RNAs “undruggable”. In an effort to develop a small molecule library that is biased for binding RNA, we computationally identified “drug-like” compounds from screening collections that have favorable properties for binding RNA and for suitability as lead drugs. As proof-of-concept, this collection was screened for binding to and modulating the cellular dysfunction of the expanded repeating RNA (r(CUG)exp) that causes myotonic dystrophy type 1. Hit compounds bind the target in cellulo, as determined by the target identification approach Competitive Chemical Cross-Linking and Isolation by Pull-down (C-ChemCLIP), and selectively improve several disease-associated defects. The best compounds identified from our 320-member library are more potent in cellulo than compounds identified by high-throughput screening (HTS) campaigns against this RNA. Furthermore, the compound collection has a higher hit rate (9% compared to 0.01–3%), and the bioactive compounds identified are not charged; thus, RNA can be “drugged” with compounds that have favorable pharmacological properties. Finally, this RNA-focused small molecule library may serve as a useful starting point to identify lead “drug-like” chemical probes that affect the biological (dys)function of other RNA targets by direct target engagement. PMID:26414664

  18. Myotonic Dystrophy Type 1 RNA Crystal Structures Reveal Heterogeneous 1 × 1 Nucleotide UU Internal Loop Conformations

    SciTech Connect

    Kumar, Amit; Park, HaJeung; Fang, Pengfei; Parkesh, Raman; Guo, Min; Nettles, Kendall W.; Disney, Matthew D.

    2012-03-27

    RNA internal loops often display a variety of conformations in solution. Herein, we visualize conformational heterogeneity in the context of the 5'CUG/3'GUC repeat motif present in the RNA that causes myotonic dystrophy type 1 (DM1). Specifically, two crystal structures of a model DM1 triplet repeating construct, 5'r[{und UU}GGGC(C{und U}G){sub 3}GUCC]{sub 2}, refined to 2.20 and 1.52 {angstrom} resolution are disclosed. Here, differences in the orientation of the 5' dangling UU end between the two structures induce changes in the backbone groove width, which reveals that noncanonical 1 x 1 nucleotide UU internal loops can display an ensemble of pairing conformations. In the 2.20 {angstrom} structure, CUGa, the 5' UU forms a one hydrogen-bonded pair with a 5' UU of a neighboring helix in the unit cell to form a pseudoinfinite helix. The central 1 x 1 nucleotide UU internal loop has no hydrogen bonds, while the terminal 1 x 1 nucleotide UU internal loops each form a one-hydrogen bond pair. In the 1.52 {angstrom} structure, CUGb, the 5' UU dangling end is tucked into the major groove of the duplex. While the canonically paired bases show no change in base pairing, in CUGb the terminal 1 x 1 nucleotide UU internal loops now form two hydrogen-bonded pairs. Thus, the shift in the major groove induced by the 5' UU dangling end alters noncanonical base patterns. Collectively, these structures indicate that 1 x 1 nucleotide UU internal loops in DM1 may sample multiple conformations in vivo. This observation has implications for the recognition of this RNA, and other repeating transcripts, by protein and small molecule ligands.

  19. Myotonic dystrophy type 1 RNA crystal structures reveal heterogeneous 1 × 1 nucleotide UU internal loop conformations.

    PubMed

    Kumar, Amit; Park, HaJeung; Fang, Pengfei; Parkesh, Raman; Guo, Min; Nettles, Kendall W; Disney, Matthew D

    2011-11-15

    RNA internal loops often display a variety of conformations in solution. Herein, we visualize conformational heterogeneity in the context of the 5'CUG/3'GUC repeat motif present in the RNA that causes myotonic dystrophy type 1 (DM1). Specifically, two crystal structures of a model DM1 triplet repeating construct, 5'r[UUGGGC(CUG)(3)GUCC](2), refined to 2.20 and 1.52 Å resolution are disclosed. Here, differences in the orientation of the 5' dangling UU end between the two structures induce changes in the backbone groove width, which reveals that noncanonical 1 × 1 nucleotide UU internal loops can display an ensemble of pairing conformations. In the 2.20 Å structure, CUGa, the 5' UU forms a one hydrogen-bonded pair with a 5' UU of a neighboring helix in the unit cell to form a pseudoinfinite helix. The central 1 × 1 nucleotide UU internal loop has no hydrogen bonds, while the terminal 1 × 1 nucleotide UU internal loops each form a one-hydrogen bond pair. In the 1.52 Å structure, CUGb, the 5' UU dangling end is tucked into the major groove of the duplex. While the canonically paired bases show no change in base pairing, in CUGb the terminal 1 × 1 nucleotide UU internal loops now form two hydrogen-bonded pairs. Thus, the shift in the major groove induced by the 5' UU dangling end alters noncanonical base patterns. Collectively, these structures indicate that 1 × 1 nucleotide UU internal loops in DM1 may sample multiple conformations in vivo. This observation has implications for the recognition of this RNA, and other repeating transcripts, by protein and small molecule ligands.

  20. Myotonic Dystrophy Type 1 RNA Crystal Structures Reveal Heterogeneous 1×1 Nucleotide UU Internal Loop Conformations⊥

    PubMed Central

    Kumar, Amit; Park, HaJeung; Fang, Pengfei; Parkesh, Raman; Guo, Min; Nettles, Kendall W.; Disney, Matthew D.

    2011-01-01

    RNA internal loops often display a variety of conformations in solution. Herein, we visualize conformational heterogeneity in the context of the 5′CUG/3′GUC repeat motif present in the RNA that causes myotonic dystrophy type 1 (DM1). Specifically, two crystal structures are disclosed of a model DM1 triplet repeating construct, 5′r(UUGGGC(CUG)3GUCC)2, refined to 2.20 Å and 1.52 Å resolution. Here, differences in orientation of the 5′ dangling UU end between the two structures induce changes in the backbone groove width, which reveals that non-canonical 1×1 nucleotide UU internal loops can display an ensemble of pairing conformations. In the 2.20 Å structure, CUGa, the 5′UU forms one hydrogen-bonded pairs with a 5′UU of a neighboring helix in the unit cell to form a pseudo-infinite helix. The central 1×1 nucleotide UU internal loop has no hydrogen bonds, while the terminal 1×1 nucleotide UU internal loops each form a one hydrogen-bonded pair. In the 1.52 Å structure, CUGb, the 5′ UU dangling end is tucked into the major groove of the duplex. While the canonical paired bases show no change in base pairing, in CUGb the terminal 1×1 nucleotide UU internal loops form now two hydrogen-bonded pairs. Thus, the shift in major groove induced by the 5′UU dangling end alters non-canonical base patterns. Collectively, these structures indicate that 1×1 nucleotide UU internal loops in DM1 may sample multiple conformations in vivo. This observation has implications for the recognition of this RNA, and other repeating transcripts, by protein and small molecule ligands. PMID:21988728

  1. Studying a Drug-like, RNA-Focused Small Molecule Library Identifies Compounds That Inhibit RNA Toxicity in Myotonic Dystrophy.

    PubMed

    Rzuczek, Suzanne G; Southern, Mark R; Disney, Matthew D

    2015-12-18

    There are many RNA targets in the transcriptome to which small molecule chemical probes and lead therapeutics are desired. However, identifying compounds that bind and modulate RNA function in cellulo is difficult. Although rational design approaches have been developed, they are still in their infancies and leave many RNAs "undruggable". In an effort to develop a small molecule library that is biased for binding RNA, we computationally identified "drug-like" compounds from screening collections that have favorable properties for binding RNA and for suitability as lead drugs. As proof-of-concept, this collection was screened for binding to and modulating the cellular dysfunction of the expanded repeating RNA (r(CUG)(exp)) that causes myotonic dystrophy type 1. Hit compounds bind the target in cellulo, as determined by the target identification approach Competitive Chemical Cross-Linking and Isolation by Pull-down (C-ChemCLIP), and selectively improve several disease-associated defects. The best compounds identified from our 320-member library are more potent in cellulo than compounds identified by high-throughput screening (HTS) campaigns against this RNA. Furthermore, the compound collection has a higher hit rate (9% compared to 0.01-3%), and the bioactive compounds identified are not charged; thus, RNA can be "drugged" with compounds that have favorable pharmacological properties. Finally, this RNA-focused small molecule library may serve as a useful starting point to identify lead "drug-like" chemical probes that affect the biological (dys)function of other RNA targets by direct target engagement.

  2. The role of flexibility in the rational design of modularly assembled ligands targeting the RNAs that cause the myotonic dystrophies.

    PubMed

    Disney, Matthew D; Lee, Melissa M; Pushechnikov, Alexei; Childs-Disney, Jessica L

    2010-02-15

    Modularly assembled ligands were designed to target the RNAs that cause two currently untreatable neuromuscular disorders, myotonic dystrophy types 1 (DM1) and 2 (DM2). DM1 is caused by an expanded repeating sequence of CUG, and DM2 is caused by expanded CCUG repeats. Both are present in noncoding regions and fold into hairpins with either repeating 1x1 nucleotide UU (DM1) or 2x2 nucleotide 5'-CU/3'-UC (DM2) internal loops separated by two GC pairs. The repeats are toxic because they sequester the RNA splicing regulator muscleblind-like 1 protein (MBNL1). Rational design of ligands targeting these RNAs was enabled by a database of RNA motif-ligand partners compiled by using two-dimensional combinatorial screening (2DCS). One 2DCS study found that the 6''-azido-kanamycin A module binds internal loops similar to those found in DM1 and DM2. In order to further enhance affinity and specificity, the ligand was assembled on a peptoid backbone to precisely control valency and the distance between ligand modules. Designed compounds are more potent and specific binders to the toxic RNAs than MBNL1 and inhibit the formation of the RNA-protein complexes with nanomolar IC(50) values. This study shows that three important factors govern potent inhibition: 1) the surface area sequestered by the assembled ligands; 2) the spacing between ligand modules since a longer distance is required to target DM2 RNAs than DM1 RNAs; and 3) flexibility in the modular assembly scaffold used to display the RNA-binding module. These results have impacts on the general design of assembled ligands targeting RNAs present in genomic sequence.

  3. High prevalence of cardiac involvement in patients with myotonic dystrophy type 1: a cross-sectional study.

    PubMed

    Petri, Helle; Witting, Nanna; Ersbøll, Mads Kristian; Sajadieh, Ahmad; Dunø, Morten; Helweg-Larsen, Susanne; Vissing, John; Køber, Lars; Bundgaard, Henning

    2014-06-01

    Patients with myotonic dystrophy type 1 (DM1) have a three-fold higher risk of sudden cardiac death (SCD) than age-matched healthy controls. Despite numerous attempts to define the cardiac phenotype and natural history, existing literature suffers from low power, selection-bias and lack of controls. Thus, the optimal strategy for assessing cardiac involvement in DM1 is unclear. In this large single-centre study, we evaluated 129 unselected DM1 patients (49.6% men), mean (SD) age 44 (14.7) years with family history, physical examination, electrocardiogram (ECG), echocardiography, Holter-monitoring and muscle strength testing. Cardiac involvement was found in 71 patients (55%) and included: 1) Conduction abnormalities: atrio-ventricular block grade I (AVB grade I) (23.6%), AVB grade II (5.6%), right/left bundle branch block (5.5/3.2%) and prolonged QTc (7.2%); 2) arrhythmias: atrial fibrillation/flutter (4.1%), other supraventricular tachyarrhythmia (7.3%) and non-sustained ventricular tachycardia (4.1%); and 3) structural abnormalities: left ventricular systolic dysfunction (20.6%) and reduced global longitudinal strain (21.7%). A normal ECG was not significantly associated with normal findings on Holter-monitoring or echocardiography. Patients with abnormal cardiac findings had weaker muscle strength than those with normal cardiac findings: ankle dorsal flexion (median (range) 4.5 (0-5) vs. 5.0 (2.5-5), p=0.004) and handgrip (median 4.0 (0-5) vs. 4.50 (2-5), p=0.02). The cardiac phenotype of DM1 includes a high prevalence of conduction disorders, arrhythmias and risk factors of SCD. Systematic cardiac screening with ECG, Holter-monitoring and echocardiography is needed in order to make a proper characterization of cardiac involvement in DM1. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Comparisons of intellectual capacities between mild and classic adult-onset phenotypes of myotonic dystrophy type 1 (DM1).

    PubMed

    Jean, Stéphane; Richer, Louis; Laberge, Luc; Mathieu, Jean

    2014-11-26

    Myotonic dystrophy type 1 (DM1) is an autosomal dominant genetic multisystem disorder and the commonest adult-onset form of muscular dystrophy. DM1 results from the expansion of an unstable trinucleotide cytosine-thymine-guanine (CTG) repeat mutation. CTG repeats in DM1 patients can range from 50 to several thousands, with a tendency toward increased repeats with successive generations (anticipation). Associated findings can include involvements in almost every systems, including the brain, and cognitive abnormalities occur in the large majority of patients. The objectives are to describe and compare the intellectual abilities of a large sample of DM1 patients with mild and classic adult-onset phenotypes, to estimate the validity of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) in DM1 patients with muscular weakness, and to appraise the relationship of intelligence quotient (IQ) to CTG repeat length, age at onset of symptoms, and disease duration. A seven-subtest WAIS-R was administered to 37 mild and 151 classic adult-onset DM1 patients to measure their Full-Scale (FSIQ), Verbal (VIQ) and Performance IQ (PIQ). To control for potential bias due to muscular weakness, Standard Progressive Matrices (SPM), a motor-independent test of intelligence, were also completed. Total mean FSIQ was 82.6 corresponding to low average IQ, and 82% were below an average intelligence. Mild DM1 patients had a higher mean FSIQ (U=88.7 vs 81.1, p<0.001), VIQ (U=87.8 vs 82.3, p=0.001), and PIQ (U=94.8 vs 83.6, p<0.001) than classic adult-onset DM1 patients. In both mild and classic adult-onset patients, all subtests mean scaled scores were below the normative sample mean. FSIQ also strongly correlate with SPM (r s =0.67, p<0.001), indicating that low intelligence scores are not a consequence of motor impairment. FSIQ scores decreased with both the increase of (CTG)n (r s =-0.41, p<0.001) and disease duration (r s =-0.26, p=0.003). Results show that intellectual impairment is an

  5. Treatment of sleep central apnea with non-invasive mechanical ventilation with 2 levels of positive pressure (bilevel) in a patient with myotonic dystrophy type 1

    PubMed Central

    Akamine, Ricardo Tera; Grossklauss, Luís Fernando; Moreira, Gustavo Antonio; Pradella-Hallinan, Marcia; Chiéia, Marco Antônio; Mesquita, Denis; Bulle Oliveira, Acary Souza; Tufik, Sergio

    2014-01-01

    We are reporting a case of a 29 year-old female with diagnosis of myotonic dystrophy type 1 (Steinert’s disease) with excessive daytime sleepiness, muscle fatigue, snoring, frequent arousals, non-restorative sleep, and witnessed apneas. Pulmonary function tests revealed a mild decrease of forced vital capacity. Nocturnal polysomnography showed an increase of apnea/hypopnea index (85.9 events/h), mainly of central type (236), minimal oxygen saturation of 72%, and end-tidal carbon dioxide values that varied from 45 to 53 mmHg. Bi-level positive airway pressure titration was initiated at an inspiratory pressure (IPAP) of 8 and an expiratory pressure (EPAP) of 4 cm H2O. IPAP was then gradually increased to eliminate respiratory events and improve oxygen saturation. An IPAP of 12cm H20 and an EPAP of 4cm H2O eliminated all respiratory events, and the oxygen saturation remained above 90%. Bi-level positive airway pressure treatment at spontaneous/timed mode showed an improvement in snoring, apneas, and Epworth sleepiness scale decreased from 20 to 10. This case illustrates the beneficial effects of Bi-level positive airway pressure support in central sleep apnea syndrome of a patient with myotonic dystrophy type 1. PMID:26483914

  6. A fly model for the CCUG-repeat expansion of myotonic dystrophy type 2 reveals a novel interaction with MBNL1.

    PubMed

    Yu, Zhenming; Goodman, Lindsey D; Shieh, Shin-Yi; Min, Michelle; Teng, Xiuyin; Zhu, Yongqing; Bonini, Nancy M

    2015-02-15

    Expanded non-coding RNA repeats of CUG and CCUG are the underlying genetic causes for myotonic dystrophy type 1 (DM1) and type 2 (DM2), respectively. A gain-of-function of these pathogenic repeat expansions is mediated at least in part by their abnormal interactions with RNA-binding proteins such as MBNL1 and resultant loss of activity of these proteins. To study pathogenic mechanisms of CCUG-repeat expansions in an animal model, we created a fly model of DM2 that expresses pure, uninterrupted CCUG-repeat expansions ranging from 16 to 720 repeats in length. We show that this fly model for DM2 recapitulates key features of human DM2 including RNA repeat-induced toxicity, ribonuclear foci formation and changes in alternative splicing. Interestingly, expression of two isoforms of MBNL1, MBNL135 and MBNL140, leads to cleavage and concurrent upregulation of the levels of the RNA-repeat transcripts, with MBNL140 having more significant effects than MBNL135. This property is shared with a fly CUG-repeat expansion model. Our results suggest a novel mechanism for interaction between the pathogenic RNA repeat expansions of myotonic dystrophy and MBNL1.

  7. Tendon Extracellular Matrix Alterations in Ullrich Congenital Muscular Dystrophy

    PubMed Central

    Sardone, Francesca; Traina, Francesco; Bondi, Alice; Merlini, Luciano; Santi, Spartaco; Maraldi, Nadir Mario; Faldini, Cesare; Sabatelli, Patrizia

    2016-01-01

    Collagen VI (COLVI) is a non-fibrillar collagen expressed in skeletal muscle and most connective tissues. Mutations in COLVI genes cause two major clinical forms, Bethlem myopathy and Ullrich congenital muscular dystrophy (UCMD). In addition to congenital muscle weakness, patients affected by COLVI myopathies show axial and proximal joint contractures and distal joint hypermobility, which suggest the involvement of the tendon function. We examined a peroneal tendon biopsy and tenocyte culture of a 15-year-old patient affected by UCMD with compound heterozygous COL6A2 mutations. In patient’s tendon biopsy, we found striking morphological alterations of tendon fibrils, consisting in irregular profiles and reduced mean diameter. The organization of the pericellular matrix of tenocytes, the primary site of collagen fibril assembly, was severely affected, as determined by immunoelectron microscopy, which showed an abnormal accumulation of COLVI and altered distribution of collagen I (COLI) and fibronectin (FBN). In patient’s tenocyte culture, COLVI web formation and cell surface association were severely impaired; large aggregates of COLVI, which matched with COLI labeling, were frequently detected in the extracellular matrix. In addition, metalloproteinase MMP-2, an extracellular matrix-regulating enzyme, was increased in the conditioned medium of patient’s tenocytes, as determined by gelatin zymography and western blot. Altogether, these data indicate that COLVI deficiency may influence the organization of UCMD tendon matrix, resulting in dysfunctional fibrillogenesis. The alterations of tendon matrix may contribute to the complex pathogenesis of COLVI related myopathies. PMID:27375477

  8. Tendon Extracellular Matrix Alterations in Ullrich Congenital Muscular Dystrophy.

    PubMed

    Sardone, Francesca; Traina, Francesco; Bondi, Alice; Merlini, Luciano; Santi, Spartaco; Maraldi, Nadir Mario; Faldini, Cesare; Sabatelli, Patrizia

    2016-01-01

    Collagen VI (COLVI) is a non-fibrillar collagen expressed in skeletal muscle and most connective tissues. Mutations in COLVI genes cause two major clinical forms, Bethlem myopathy and Ullrich congenital muscular dystrophy (UCMD). In addition to congenital muscle weakness, patients affected by COLVI myopathies show axial and proximal joint contractures and distal joint hypermobility, which suggest the involvement of the tendon function. We examined a peroneal tendon biopsy and tenocyte culture of a 15-year-old patient affected by UCMD with compound heterozygous COL6A2 mutations. In patient's tendon biopsy, we found striking morphological alterations of tendon fibrils, consisting in irregular profiles and reduced mean diameter. The organization of the pericellular matrix of tenocytes, the primary site of collagen fibril assembly, was severely affected, as determined by immunoelectron microscopy, which showed an abnormal accumulation of COLVI and altered distribution of collagen I (COLI) and fibronectin (FBN). In patient's tenocyte culture, COLVI web formation and cell surface association were severely impaired; large aggregates of COLVI, which matched with COLI labeling, were frequently detected in the extracellular matrix. In addition, metalloproteinase MMP-2, an extracellular matrix-regulating enzyme, was increased in the conditioned medium of patient's tenocytes, as determined by gelatin zymography and western blot. Altogether, these data indicate that COLVI deficiency may influence the organization of UCMD tendon matrix, resulting in dysfunctional fibrillogenesis. The alterations of tendon matrix may contribute to the complex pathogenesis of COLVI related myopathies.

  9. [Spinal muscular atrophy mimicking myotonic dystrophy: a case report and clinical, pathological and genetic analysis].

    PubMed

    Luo, Li-xia; Pan, Qian; Xia, Kun; Tang, Bei-sha; Jiang, Hong

    2012-08-01

    To investigate a patient featuring a complex neuromuscular disease phenotype. A comprehensive analysis integrating clinical investigation, electrophysiological testing, pathological analysis and mutation screening was carried out. The patient has presented clinical and pathological manifestations mimicking Duchenne muscular dystrophy. However, genetic analysis has identified no deletion in 21 exons of Dystrophin gene, no pathologic expansion of CTG repeats in DMPK gene or CCTG repeats in ZFN9 gene. Instead, a homozygous deletion of exons 7 and 8 in SMN gene was discovered. A rare case of spinal muscular atrophy (SMA) was verified by genetic diagnosis. SMA is a group of neuromuscular disorders with great phenotypic heterogeneity and sometimes cannot be diagnosed by clinical manifestations, electrophysiological and pathological changes alone. Genetic diagnosis has become indispensable for accurate diagnosis for patients suspected to have the disease.

  10. Functional impairment in patients with myotonic dystrophy type 1 can be assessed by an ataxia rating scale (SARA).

    PubMed

    DiPaolo, Giovanni; Jimenez-Moreno, Cecilia; Nikolenko, Nikoletta; Atalaia, Antonio; Monckton, Darren G; Guglieri, Michela; Lochmüller, Hanns

    2017-04-01

    Myotonic dystrophy type 1 (DM1) is not characterised by ataxia per se; however, DM1 and ataxia patients show similar disturbances in movement coordination often experiencing walking and balance difficulties, although caused by different underlying pathologies. This study aims to investigate the use of a scale previously described for the assessment and rating of ataxia (SARA) with the hypothesis that it could have utility in DM1 patients as a measure of disease severity and risk of falling. Data from 54 DM1 patients were pulled from the PHENO-DM1 natural history study for analysis. Mean SARA score in the DM1 population was 5.45 relative to the maximum score of eight. A flooring effect (score 0) was observed in mild cases within the sample. Inter-rater and test-retest reliability was high with intraclass coefficients (ICC) of 0.983 and 1.00, respectively. Internal consistency was acceptable as indicated by a Cronbach's alpha of 0.761. Component analysis revealed two principle components. SARA correlated with: (1) all measures of muscle function tested, including quantitative muscle testing of ankle dorsiflexion (r = -0.584*), the 6 min walk test (r = -0.739*), 10 m walk test (r = 0.741*), and the nine hole peg test (r = 0.602*) and (2) measures of disease severity/burden, such as MIRS (r = 0.718*), MDHI (r = 0.483*), and DM1-Activ (r = -0.749*) (*p < 0.001). The SARA score was predicted by an interaction between modal CTG repeat length and age at sampling (r = 0.678, p = 0.003). A score of eight or above predicted the use of a walking aid with a sensitivity of 100% and a specificity of 85.7%. We suggest that further research is warranted to ascertain whether SARA or components of SARA are useful outcome measures for clinical trials in DM1. As a tool, it can be used for gathering information about disease severity/burden and helping to identify patients in need of a walking aid, and can potentially be applied in both research and healthcare

  11. The effect of atrial preference pacing on atrial fibrillation electrophysiological substrate in Myotonic Dystrophy type 1 population.

    PubMed

    Russo, Vincenzo; Nigro, Gerardo; DI Meo, Federica; Papa, Andrea Antonio; Cioppa, Nadia Della; Proietti, Riccardo; Russo, Maria Giovanna; Calabrò, Raffaele; Politano, Luisa

    2014-12-01

    P-wave dispersion is a non invasive indicator of intra-atrial conduction heterogeneity producing substrate for reentry, which is a pathophysiological mechanism of atrial fibrillation. The relationship between P-wave dispersion (PD) and atrial fibrillation (AF) in Myotonic dystrophy type 1 (DM1) patients is still unclear. Atrial Preference Pacing (APP) is an efficient algorithm to prevent paroxysmal AF in patients implanted with dual-chamber pacemaker. Aim of our study was to evaluate the possible correlation between atrial preference pacing algorithm, P-wave dispersion and AF burden in DM1 patients with normal cardiac function underwent permanent dual-chamber pacemaker implantation. We enrolled 50 patients with DM1 (age 50.3 ± 7.3; 11 F) underwent dual-chamber pacemaker implantation for various degree of atrioventricula block. The study population was randomized following 1 months stabilization period to APP algorithm features programmed OFF or ON. Patients were assessed every 3 months for the first year, and every 6 months thereafter up to 3 years. At each follow-up visit, we counted: the number of premature atrial beats, the number and the mean duration of AF episodes, AF burden and the percentage of atrial and ventricular pacing. APP ON Group showed lower number of AF episodes (117 ± 25 vs. 143 ± 37; p = 0.03) and AF burden (3059 ± 275 vs. 9010 ± 630 min; p < 0.04) than APP OFF Group. Atrial premature beats count (44903 ± 30689 vs. 13720 ± 7717 beats; p = 0.005) and Pwave dispersion values (42,1 ± 11 ms vs. 29,1 ± 4,2 ms, p = 0,003) were decreased in APP ON Group. We found a significant positive correlation between PD and AF burden (R = 0,8, p = 0.007). Atrial preference pacing algorithm, decreasing the number of atrial premature beats and the P-wave dispersion, reduces the onset and perpetuator factors of AF episodes and decreases the AF burden in DM1 patients underwent dual chamber pacemaker implantation for various degree of atrioventricular blocks

  12. ClC1 chloride channel in myotonic dystrophy type 2 and ClC1 splicing in vitro.

    PubMed

    Ursu, Simona-Felicia; Alekov, Alexi; Mao, Ning-Hui; Jurkat-Rott, Karin

    2012-10-01

    Myotonic dystrophy type 2 (DM2) is caused by CCTG-repeat expansions. Occurrence of splicing and mutations in the muscle chloride channel gene CLCN1 have been reported to contribute to the phenotype. To examine the effect of CLCN1 in DM2 in Germany, we determined the frequency of a representative ClC1 mutation, R894X, and its effect on DM2 clinical features. Then, we examined CLCN1 mRNA splice variants in patient muscle functionally expressed the most abundant variant, and determined its subcellular localization. Finally, we established a cellular system for studying mouse clcn1 pre-mRNA splicing and tested effects of expression of (CCUG)₁₈, (CUG)₂₄ and (AAG)₂₄ RNAs. The R894X mutation was present in 7.7% of DM2 families. DM2 R894X-carriers had more myotonia and myalgia than non-carriers. The most abundant CLCN1 splice variant in DM2 (80% of all transcripts) excluded exons 6-7 and lead to a truncated ClC1(236X) protein. Heterologous ClC1(236X) expression did not yield functional channels. Co-expression with ClC1 did not show a dominant negative effect, but a slightly suppressive effect. In C₂C₁₂ cells, the clc1 splice variants generated by (CCUG)₁₈-RNA resembled those in DM2 muscle and differed from those generated by (CUG)₂₄ and (AAG)₂₄. We conclude that ClC1 mutations exert gene dose effects and enhance myotonia and pain in DM2 in Germany. Additionally, the ClC1(236X) splice variant may contribute to myotonia in DM2. Since splice variants depend on the types of repeats expressed in the cellular C₂C₁₂ model, similar cell models of other tissues may be useful for studying repeatdependent pathogenetic mechanisms more easily than in transgenic animals.

  13. The Congenital Muscular Dystrophies: Recent Advances and Molecular Insights

    PubMed Central

    Mendell, Jerry R.; Boué, Daniel R.; Martin, Paul T.

    2010-01-01

    Over the past decade, molecular understanding of the congenital muscular dystrophies (CMDs) has greatly expanded. The diseases can be classified into 3 major groups based on the affected genes and the location of their expressed protein: abnormalities of extracellular matrix proteins (LAMA2, COL6A1, COL6A2, COL6A3), abnormalities of membrane receptors for the extracellular matrix (fukutin, POMGnT1, POMT1, POMT2, FKRP, LARGE, and ITGA7), and abnormal endoplasmic reticulum protein (SEPN1). The diseases begin in the perinatal period or shortly thereafter. A specific diagnosis can be challenging because the muscle pathology is usually not distinctive. Immunostaining of muscle using a battery of antibodies can help define a disorder that will need confirmation by gene testing. In muscle diseases with overlapping pathological features, such as CMD, careful attention to the clinical clues (e.g., family history, central nervous system features) can help guide the battery of immunostains necessary to target an unequivocal diagnosis. PMID:17163796

  14. Selective inhibition of MBNL1–CCUG interaction by small molecules toward potential therapeutic agents for myotonic dystrophy type 2 (DM2)†

    PubMed Central

    Wong, Chun-Ho; Fu, Yuan; Ramisetty, Sreenivasa Rao; Baranger, Anne M.; Zimmerman, Steven C.

    2011-01-01

    Myotonic dystrophy type 2 (DM2) is an incurable neuromuscular disease caused by expanded CCUG repeats that may exhibit toxicity by sequestering the splicing regulator MBNL1. A series of triaminotriazine- and triaminopyrimidine-based small molecules (ligands 1–3) were designed, synthesized and tested as inhibitors of the MBNL1–CCUG interaction. Despite the structural similarities of the triaminotriazine and triaminopyrimidine units, the triaminopyrimidine-based ligands bind with low micromolar affinity to CCUG repeats (Kd ∼ 0.1–3.6 µM) whereas the triaminotriazine ligands do not bind CCUG repeats. Importantly, these simple and small triaminopyrimidine ligands exhibit both strong inhibition (Ki ∼ 2 µM) of the MBNL1–CCUG interaction and high selectivity for CCUG repeats over other RNA targets. These experiments suggest these compounds are potential lead agents for the treatment of DM2. PMID:21768123

  15. Congenital hereditary endothelial dystrophy with progressive sensorineural deafness (Harboyan syndrome).

    PubMed

    Desir, Julie; Abramowicz, Marc

    2008-10-15

    Harboyan syndrome is a degenerative corneal disorder defined as congenital hereditary endothelial dystrophy (CHED) accompanied by progressive, postlingual sensorineural hearing loss. To date, 24 cases from 11 families of various origin (Asian Indian, South American Indian, Sephardi Jewish, Brazilian Portuguese, Dutch, Gypsy, Moroccan, Dominican) have been reported. More than 50% of the reported cases have been associated with parental consanguinity. The ocular manifestations in Harboyan syndrome include diffuse bilateral corneal edema occurring with severe corneal clouding, blurred vision, visual loss and nystagmus. They are apparent at birth or within the neonatal period and are indistinguishable from those characteristic of the autosomal recessive CHED (CHED2). Hearing deficit in Harboyan is slowly progressive and typically found in patients 10-25 years old. There are no reported cases with prelinglual deafness, however, a significant hearing loss in children as young as 4 years old has been detected by audiometry, suggesting that hearing may be affected earlier, even at birth. Harboyan syndrome is caused by mutations in the SLC4A11 gene located at the CHED2 locus on chromosome 20p13-p12, indicating that CHED2 and Harboyan syndrome are allelic disorders. A total of 62 different SLC4A11 mutations have been reported in 98 families (92 CHED2 and 6 Harboyan). All reported cases have been consistent with autosomal recessive transmission. Diagnosis is based on clinical criteria, detailed ophthalmological assessment and audiometry. A molecular confirmation of the clinical diagnosis is feasible. A variety of genetic, metabolic, developmental and acquired diseases presenting with clouding of the cornea should be considered in the differential diagnosis (Peters anomaly, sclerocornea, limbal dermoids, congenital glaucoma). Audiometry must be performed to differentiate Harboyan syndrome from CHED2. Autosomal recessive types of CHED (CHED2 and Harboyan syndrome) should

  16. Rasch Analysis of the Motor Function Measure in Patients With Congenital Muscle Dystrophy and Congenital Myopathy

    PubMed Central

    Vuillerot, Carole; Rippert, Pascal; Kinet, Virginie; Renders, Anne; Jain, Minal; Waite, Melissa; Glanzman, Allan M.; Girardot, Francoise; Hamroun, Dalil; Iwaz, Jean; Ecochard, René; Quijano-Roy, Susana; Bérard, Carole; Poirot, Isabelle; Bönnemann, Carsten G.

    2016-01-01

    Objectives To monitor treatment effects in patients with congenital myopathies and congenital muscular dystrophies, valid outcome measures are necessary. The Motor Function Measure (MFM) was examined for robustness, and changes are proposed for better adequacy. Design Observational study based on data previously collected from several cohorts. Setting Nineteen departments of physical medicine or neuromuscular consultation in France, Belgium, and the United States. Participants Patients (N=289) aged 5 to 77 years. Interventions None. Main Outcome Measures A Rasch analysis examined the robustness of the MFM across the disease spectrum. The 3 domains of the scale (standing position and transfers, axial and proximal motor function, and distal motor function) were independently examined with a partial credit model. Results The original 32-item MFM did not sufficiently fit the Rasch model expectations in either of its domains. Switching from a 4- to a 3-category response scale in 18 items restored response order in 16. Various additional checks suggested the removal of 7 items. The resulting Rasch-scaled Motor Function Measure with 25 items for congenital disorders of the muscle (Rs-MFM25CDM) demonstrated a good fit to the Rasch model. Domain 1 was well targeted to the whole severity spectrum—close mean locations for items and persons (0 vs 0.316)—whereas domains 2 and 3 were better targeted to severe cases. The reliability coefficients of the Rs-MFM25CDM suggested sufficient ability for each summed score to distinguish between patient groups (0.9, 0.8, and 0.7 for domains 1, 2, and 3, respectively). A sufficient agreement was found between results of the Rasch analysis and physical therapists’ opinions. Conclusions The Rs-MFM25CDM can be considered a clinically relevant linear scale in each of its 3 domains and may be soon reliably used for assessment in congenital disorders of the muscle. PMID:24973498

  17. Learning about Myotonic Dystrophy

    MedlinePlus

    ... Links for Patient Care Education All About the Human Genome Project Fact Sheets Genetic Education Resources for Teachers Genomic Careers National DNA Day Online Education Kit Online Genetics Education ... Subjects Research Informed Consent for Genomics Research Intellectual ...

  18. Analysing regenerative potential in zebrafish models of congenital muscular dystrophy.

    PubMed

    Wood, A J; Currie, P D

    2014-11-01

    The congenital muscular dystrophies (CMDs) are a clinically and genetically heterogeneous group of muscle disorders. Clinically hypotonia is present from birth, with progressive muscle weakness and wasting through development. For the most part, CMDs can mechanistically be attributed to failure of basement membrane protein laminin-α2 sufficiently binding with correctly glycosylated α-dystroglycan. The majority of CMDs therefore arise as the result of either a deficiency of laminin-α2 (MDC1A) or hypoglycosylation of α-dystroglycan (dystroglycanopathy). Here we consider whether by filling a regenerative medicine niche, the zebrafish model can address the present challenge of delivering novel therapeutic solutions for CMD. In the first instance the readiness and appropriateness of the zebrafish as a model organism for pioneering regenerative medicine therapies in CMD is analysed, in particular for MDC1A and the dystroglycanopathies. Despite the recent rapid progress made in gene editing technology, these approaches have yet to yield any novel zebrafish models of CMD. Currently the most genetically relevant zebrafish models to the field of CMD, have all been created by N-ethyl-N-nitrosourea (ENU) mutagenesis. Once genetically relevant models have been established the zebrafish has several important facets for investigating the mechanistic cause of CMD, including rapid ex vivo development, optical transparency up to the larval stages of development and relative ease in creating transgenic reporter lines. Together, these tools are well suited for use in live-imaging studies such as in vivo modelling of muscle fibre detachment. Secondly, the zebrafish's contribution to progress in effective treatment of CMD was analysed. Two approaches were identified in which zebrafish could potentially contribute to effective therapies. The first hinges on the augmentation of functional redundancy within the system, such as upregulating alternative laminin chains in the candyfloss

  19. Myotonic disorders: A review article

    PubMed Central

    Hahn, Chris; Salajegheh, Mohammad Kian

    2016-01-01

    The myotonic disorders are a heterogeneous group of genetically determined diseases that are unified by the presence of myotonia, which is defined as failure of muscle relaxation after activation. The presentation of these disorders can range from asymptomatic electrical myotonia, as seen in some forms of myotonia congenita (MC), to severe disability with muscle weakness, cardiac conduction defects, and other systemic features as in myotonic dystrophy type I (DM1). In this review, we describe the clinical features and pathophysiology of the different myotonic disorders, their laboratory and electrophysiologic findings and briefly review the currently available treatments. PMID:27141276

  20. Lack of correlation between the ventilatory response to CO2 and lung function impairment in myotonic dystrophy patients: evidence for a dysregulation at central level.

    PubMed

    Poussel, Mathias; Thil, Catherine; Kaminsky, Pierre; Mercy, Magalie; Gomez, Emmanuel; Chaouat, Ari; Chabot, François; Chenuel, Bruno

    2015-05-01

    Myotonic dystrophy Type 1 (DM1) is the most common muscular dystrophy in adults. Respiratory failure is common but clinical findings support a dysregulation of the control of breathing at central level, furthermore contributing to alveolar hypoventilation independently of the severity of respiratory weakness. We therefore intended to study the relationship between the ventilatory response to CO2 and the impairment of lung function in DM1 patients. Sixty-nine DM1 patients were prospectively investigated (43.5 ± 12.7 years). Systematic pulmonary lung function evaluation including spirometry, plethysmography, measurements of respiratory muscle strength, arterial blood gas analysis and ventilatory response to CO2 were performed. Thirty-one DM1 patients (45%) presented a ventilatory restriction, 38 (55%) were hypoxaemic and 15 (22%) were hypercapnic. Total lung capacity decline was correlated to hypoxaemia (p = 0.0008) and hypercapnia (p = 0.0013), but not to a decrease in ventilatory response to CO2 (p = 0.194). Ventilatory response to CO2 was reduced to 0.85 ± 0.67 L/min/mmHg and not correlated to respiratory muscle weakness. Ventilatory response to CO2 was neither different among restricted/non-restricted patients (p = 0.2395) nor among normoxaemic/hypoxaemic subjects (p = 0.6380). The reduced ventilatory response to CO2 in DM1 patients appeared independent of lung function impairment and respiratory muscle weakness, suggesting a central cause of CO2 insensitivity.

  1. Identification and Characterization of Modified Antisense Oligonucleotides Targeting DMPK in Mice and Nonhuman Primates for the Treatment of Myotonic Dystrophy Type 1

    PubMed Central

    Wheeler, Thurman M.; Justice, Samantha L.; Kim, Aneeza; Younis, Husam S.; Gattis, Danielle; Jauvin, Dominic; Puymirat, Jack; Swayze, Eric E.; Freier, Susan M.; Bennett, C. Frank; Thornton, Charles A.; MacLeod, A. Robert

    2015-01-01

    Myotonic dystrophy type 1 (DM1) is the most common form of muscular dystrophy in adults. DM1 is caused by an expanded CTG repeat in the 3′-untranslated region of DMPK, the gene encoding dystrophia myotonica protein kinase (DMPK). Antisense oligonucleotides (ASOs) containing 2′,4′-constrained ethyl-modified (cEt) residues exhibit a significantly increased RNA binding affinity and in vivo potency relative to those modified with other 2′-chemistries, which we speculated could translate to enhanced activity in extrahepatic tissues, such as muscle. Here, we describe the design and characterization of a cEt gapmer DMPK ASO (ISIS 486178), with potent activity in vitro and in vivo against mouse, monkey, and human DMPK. Systemic delivery of unformulated ISIS 486718 to wild-type mice decreased DMPK mRNA levels by up to 90% in liver and skeletal muscle. Similarly, treatment of either human DMPK transgenic mice or cynomolgus monkeys with ISIS 486178 led to up to 70% inhibition of DMPK in multiple skeletal muscles and ∼50% in cardiac muscle in both species. Importantly, inhibition of DMPK was well tolerated and was not associated with any skeletal muscle or cardiac toxicity. Also interesting was the demonstration that the inhibition of DMPK mRNA levels in muscle was maintained for up to 16 and 13 weeks post-treatment in mice and monkeys, respectively. These results demonstrate that cEt-modified ASOs show potent activity in skeletal muscle, and that this attractive therapeutic approach warrants further clinical investigation to inhibit the gain-of-function toxic RNA underlying the pathogenesis of DM1. PMID:26330536

  2. Phenylbutazone induces expression of MBNL1 and suppresses formation of MBNL1-CUG RNA foci in a mouse model of myotonic dystrophy

    PubMed Central

    Chen, Guiying; Masuda, Akio; Konishi, Hiroyuki; Ohkawara, Bisei; Ito, Mikako; Kinoshita, Masanobu; Kiyama, Hiroshi; Matsuura, Tohru; Ohno, Kinji

    2016-01-01

    Myotonic dystrophy type 1 (DM1) is caused by abnormal expansion of CTG repeats in the 3′ untranslated region of the DMPK gene. Expanded CTG repeats are transcribed into RNA and make an aggregate with a splicing regulator, MBNL1, in the nucleus, which is called the nuclear foci. The nuclear foci sequestrates and downregulates availability of MBNL1. Symptomatic treatments are available for DM1, but no rational therapy is available. In this study, we found that a nonsteroidal anti-inflammatory drug (NSAID), phenylbutazone (PBZ), upregulated the expression of MBNL1 in C2C12 myoblasts as well as in the HSALR mouse model for DM1. In the DM1 mice model, PBZ ameliorated aberrant splicing of Clcn1, Nfix, and Rpn2. PBZ increased expression of skeletal muscle chloride channel, decreased abnormal central nuclei of muscle fibers, and improved wheel-running activity in HSALR mice. We found that the effect of PBZ was conferred by two distinct mechanisms. First, PBZ suppressed methylation of an enhancer region in Mbnl1 intron 1, and enhanced transcription of Mbnl1 mRNA. Second, PBZ attenuated binding of MBNL1 to abnormally expanded CUG repeats in cellulo and in vitro. Our studies suggest that PBZ is a potent therapeutic agent for DM1 that upregulates availability of MBNL1. PMID:27126921

  3. Assessing upper extremity capacity as a potential indicator of needs related to household activities for rehabilitation services in people with myotonic dystrophy type 1.

    PubMed

    Raymond, Kateri; Auger, Louis-Pierre; Cormier, Marie-France; Vachon, Christine; St-Onge, Sabrina; Mathieu, Jean; Noreau, Luc; Gagnon, Cynthia

    2015-06-01

    This study aimed to assess upper extremity capacity as a potential indicator of needs related to household activities for rehabilitation services in people with myotonic dystrophy type 1 (DM1). A cross-sectional study was set in an outpatient neuromuscular clinic where 200 adults with a confirmed diagnosis of DM1 (121 women; mean age: 47 y) were selected from the registry of a neuromuscular clinic to participate. Housing-related activities were assessed using the "housing" section of the Assessment of Life Habits Questionnaire (LIFE-H). The upper extremity assessment included grip strength (Jamar dynamometer), lateral pinch strength (pinch gauge), gross dexterity (Box and Block Test) and fine dexterity (Purdue Pegboard Test). Correlations with the LIFE-H item "housing" were stronger for grip and lateral strength (r = 0.62; 0.61). When difficulties were present in "housing", the cut-off score associated with lateral pinch strength was 4.8 kg (sensitivity: 75.6%; specificity: 79.2%). Grip strength presented cut-off scores that clinically differed by gender. In conclusion, potential indicator of needs related to household activities for rehabilitation services with valid assessment tools were developed for people with DM1 who experience difficulties in housing-related activities. These criteria will assist health professionals in their attempt to refer DM1 patients to rehabilitation services at the appropriate time. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Muscle force, balance and falls in muscular impaired individuals with myotonic dystrophy type 1: a five-year prospective cohort study.

    PubMed

    Hammarén, Elisabet; Kjellby-Wendt, Gunilla; Lindberg, Christopher

    2015-02-01

    Individuals with myotonic dystrophy type 1 (DM1) have progressive muscle weakness with gait and balance impairments. We explored prospectively the natural history of muscle force, gait, balance, balance confidence and walking ability in muscular affected individuals with DM1. After five years data from 43 individuals (m/f:18/25) were analysed. All measures of balance showed statistically significant deterioration (p < 0.001) with averaged yearly loss of function by 3-4%. In the group as a whole, loss of muscle force was statistically significant in all lower limb muscles measured after five years: changes relative to baseline force were median -6% to -18%. For males muscle force loss was statistically significant in all leg muscles, but only in hip flexors for women. After five years 100% of the men had fallen during the previous year and 67% three times or more, in contrast only 60% of the women had fallen in the previous year and 36% three times or more. The proportion of individuals seeking medical care the previous year, after falling, was more than doubled after five years, albeit the number of falls had not changed. Awareness of this increased risk of falls is important for caregivers and patients.

  5. CRISPR/Cas9-Induced (CTG⋅CAG)n Repeat Instability in the Myotonic Dystrophy Type 1 Locus: Implications for Therapeutic Genome Editing.

    PubMed

    van Agtmaal, Ellen L; André, Laurène M; Willemse, Marieke; Cumming, Sarah A; van Kessel, Ingeborg D G; van den Broek, Walther J A A; Gourdon, Geneviève; Furling, Denis; Mouly, Vincent; Monckton, Darren G; Wansink, Derick G; Wieringa, Bé

    2017-01-04

    Myotonic dystrophy type 1 (DM1) is caused by (CTG⋅CAG)n-repeat expansion within the DMPK gene and thought to be mediated by a toxic RNA gain of function. Current attempts to develop therapy for this disease mainly aim at destroying or blocking abnormal properties of mutant DMPK (CUG)n RNA. Here, we explored a DNA-directed strategy and demonstrate that single clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-cleavage in either its 5' or 3' unique flank promotes uncontrollable deletion of large segments from the expanded trinucleotide repeat, rather than formation of short indels usually seen after double-strand break repair. Complete and precise excision of the repeat tract from normal and large expanded DMPK alleles in myoblasts from unaffected individuals, DM1 patients, and a DM1 mouse model could be achieved at high frequency by dual CRISPR/Cas9-cleavage at either side of the (CTG⋅CAG)n sequence. Importantly, removal of the repeat appeared to have no detrimental effects on the expression of genes in the DM1 locus. Moreover, myogenic capacity, nucleocytoplasmic distribution, and abnormal RNP-binding behavior of transcripts from the edited DMPK gene were normalized. Dual sgRNA-guided excision of the (CTG⋅CAG)n tract by CRISPR/Cas9 technology is applicable for developing isogenic cell lines for research and may provide new therapeutic opportunities for patients with DM1.

  6. Expanded CCUG repeat RNA expression in Drosophila heart and muscle trigger Myotonic Dystrophy type 1-like phenotypes and activate autophagocytosis genes.

    PubMed

    Cerro-Herreros, Estefania; Chakraborty, Mouli; Pérez-Alonso, Manuel; Artero, Rubén; Llamusí, Beatriz

    2017-06-06

    Myotonic dystrophies (DM1-2) are neuromuscular genetic disorders caused by the pathological expansion of untranslated microsatellites. DM1 and DM2, are caused by expanded CTG repeats in the 3'UTR of the DMPK gene and CCTG repeats in the first intron of the CNBP gene, respectively. Mutant RNAs containing expanded repeats are retained in the cell nucleus, where they sequester nuclear factors and cause alterations in RNA metabolism. However, for unknown reasons, DM1 is more severe than DM2. To study the differences and similarities in the pathogenesis of DM1 and DM2, we generated model flies by expressing pure expanded CUG ([250]×) or CCUG ([1100]×) repeats, respectively, and compared them with control flies expressing either 20 repeat units or GFP. We observed surprisingly severe muscle reduction and cardiac dysfunction in CCUG-expressing model flies. The muscle and cardiac tissue of both DM1 and DM2 model flies showed DM1-like phenotypes including overexpression of autophagy-related genes, RNA mis-splicing and repeat RNA aggregation in ribonuclear foci along with the Muscleblind protein. These data reveal, for the first time, that expanded non-coding CCUG repeat-RNA has similar in vivo toxicity potential as expanded CUG RNA in muscle and heart tissues and suggests that specific, as yet unknown factors, quench CCUG-repeat toxicity in DM2 patients.

  7. A putative role of ribonuclear inclusions and MBNL1 in the impairment of gallbladder smooth muscle contractility with cholelithiasis in myotonic dystrophy type 1.

    PubMed

    Cardani, R; Mancinelli, E; Saino, G; Bonavina, L; Meola, G

    2008-08-01

    Myotonic dystrophy type 1 (DM1) is an autosomal dominant multisystemic disorder caused by expansion of unstable trinucleotide (CTG) repeats at 3' untranslated region of the DMPK gene on chromosome 19q13.3. Mutant transcripts are retained in muscle nuclei as ribonuclear inclusions and interact with RNA-binding proteins, such as muscleblind-like protein 1 (MBNL1), leading to a reduction in their activity. The reduced MBNL1 activity has been associated to skeletal and cardiac muscle dysfunction. However, other organs and systems may be involved. It has been reported that 25-50% of DM1 patients have abdominal symptoms due to cholelithiasis or gallstones. Since impaired gallbladder motility plays an important role in gallstones formation, we have analyzed by FISH combined with MBNL1-immunofluorescence, the gallbladder obtained from a woman affected by DM1 who required a cholecystectomy at the age of 30. Gallbladders obtained from two no-DM1 subjects have been used as controls. Ribonuclear inclusions and MBNL1 foci accumulate and colocalize in nuclei of DM1 gallbladder smooth muscle cells. On the contrary, no ribonuclear inclusions are detectable in cell nuclei of control gallbladders and MBNL1 is uniformly distributed in smooth muscle cell nuclei. These results suggest that nuclear accumulation of MBNL1 and ribonuclear inclusions may have a direct adverse effect on gallbladder smooth muscle contractility and thus contribute to gallstones formation in DM1 patients.

  8. Quantitative Assessment of Trunk Muscles Involvement in Patients with Myotonic Dystrophy Type 1 Using a Whole Body Muscle Magnetic Resonance Imaging.

    PubMed

    Park, Donghwi; Park, Jin-Sung

    2017-01-01

    The aim of this study was to analyze the pattern of trunk muscles involvement through a muscle MRI, in relation to the clinical data of patients diagnosed with myotonic dystrophy type 1 (DM1). Patients with DM1 who visited the neurology department were enrolled (n = 19). In all patients, the fatty degeneration of the muscle MRI in the lower cervical, upper thoracic, middle thoracic, and lumbosacral spine extensor muscle group and trunk flexor muscle group was evaluated. Clinical data, including CTG repeats, spinal deformity were analyzed to find the correlations with the fatty degeneration of trunk muscles in the muscle MRI. All DM1 patients who presented with very mild to severe functional status showed T1-weghted high intensity signals in the upper-thoracic spine extensor muscle group. The sum MRI score of the spine extensor muscle group showed a significant correlation with the 6-min walking test, and Cobb's angle. DM1 frequently affects the trunk muscles, even in the early stage of disease progression, regardless of disease severity or age of onset. Among the para-vertebral muscles, the selective involvement of spine extensor muscles may explain the cause of spinal deformities, which mirrors the functional status of DM1. © 2017 S. Karger AG, Basel.

  9. Muscle weakness in myotonic dystrophy associated with misregulated splicing and altered gating of CaV1.1 calcium channel

    PubMed Central

    Tang, Zhen Zhi; Yarotskyy, Viktor; Wei, Lan; Sobczak, Krzysztof; Nakamori, Masayuki; Eichinger, Katy; Moxley, Richard T.; Dirksen, Robert T.; Thornton, Charles A.

    2012-01-01

    Myotonic dystrophy type 1 and type 2 (DM1 and DM2) are genetic diseases in which mutant transcripts containing expanded CUG or CCUG repeats cause cellular dysfunction by altering the processing or metabolism of specific mRNAs and miRNAs. The toxic effects of mutant RNA are mediated partly through effects on proteins that regulate alternative splicing. Here we show that alternative splicing of exon 29 (E29) of CaV1.1, a calcium channel that controls skeletal muscle excitation–contraction coupling, is markedly repressed in DM1 and DM2. The extent of E29 skipping correlated with severity of weakness in tibialis anterior muscle of DM1 patients. Two splicing factors previously implicated in DM1, MBNL1 and CUGBP1, participated in the regulation of E29 splicing. In muscle fibers of wild-type mice, the CaV1.1 channel conductance and voltage sensitivity were increased by splice-shifting oligonucleotides that induce E29 skipping. In contrast to human DM1, expression of CUG-expanded RNA caused only a modest increase in E29 skipping in mice. However, forced skipping of E29 in these mice, to levels approaching those observed in human DM1, aggravated the muscle pathology as evidenced by increased central nucleation. Together, these results indicate that DM-associated splicing defects alter CaV1.1 function, with potential for exacerbation of myopathy. PMID:22140091

  10. LDB3 splicing abnormalities are specific to skeletal muscles of patients with myotonic dystrophy type 1 and alter its PKC binding affinity.

    PubMed

    Yamashita, Yoshihiro; Matsuura, Tohru; Kurosaki, Tatsuaki; Amakusa, Yoshinobu; Kinoshita, Masanobu; Ibi, Tohru; Sahashi, Ko; Ohno, Kinji

    2014-09-01

    Myotonic dystrophy type 1 (DM1) is caused by transcription of CUG repeat RNA, which causes sequestration of muscleblind-like 1 (MBNL1) and upregulation of CUG triplet repeat RNA-binding protein (CUG-BP1). In DM1, dysregulation of these proteins contributes to many aberrant splicing events, causing various symptoms of the disorder. Here, we demonstrate the occurrence of aberrant splicing of LIM domain binding 3 (LDB3) exon 11 in DM1 skeletal muscle. Exon array surveys, RT-PCR, and western blotting studies demonstrated that exon 11 inclusion was DM1 specific and could be reproduced by transfection of a minigene containing the CTG repeat expansion. Moreover, we found that the LDB3 exon 11-positive isoform had reduced affinity for PKC compared to the exon 11-negative isoform. Since PKC exhibits hyperactivation in DM1 and stabilizes CUG-BP1 by phosphorylation, aberrant splicing of LDB3 may contribute to CUG-BP1 upregulation through changes in its affinity for PKC.

  11. A syndrome of congenital retinal dystrophy and saccade palsy--a subset of Leber's amaurosis.

    PubMed Central

    Moore, A. T.; Taylor, D. S.

    1984-01-01

    Three children who presented in infancy with a severe visual defect and absent or barely recordable electroretinograms, with relatively well preserved visually evoked cortical potentials, were subsequently found to have vertical and horizontal saccade palsies with head thrusts but relatively good visual acuity. These children, who were clearly different from other infants with congenital retinal dystrophy, were also developmentally delayed and had systemic motor and speech defects, but their visual prognosis was relatively good. The recognition of their saccade palsy was delayed because their poor visual attention in infancy was ascribed purely to the tapetoretinal degeneration. We consider these patients represent a clear subset of those patients who are diagnosed as having congenital retinal dystrophy or Leber's amaurosis. Images PMID:6722075

  12. A syndrome of congenital retinal dystrophy and saccade palsy--a subset of Leber's amaurosis.

    PubMed

    Moore, A T; Taylor, D S

    1984-06-01

    Three children who presented in infancy with a severe visual defect and absent or barely recordable electroretinograms, with relatively well preserved visually evoked cortical potentials, were subsequently found to have vertical and horizontal saccade palsies with head thrusts but relatively good visual acuity. These children, who were clearly different from other infants with congenital retinal dystrophy, were also developmentally delayed and had systemic motor and speech defects, but their visual prognosis was relatively good. The recognition of their saccade palsy was delayed because their poor visual attention in infancy was ascribed purely to the tapetoretinal degeneration. We consider these patients represent a clear subset of those patients who are diagnosed as having congenital retinal dystrophy or Leber's amaurosis.

  13. Cardiac manifestations of congenital LMNA-related muscular dystrophy in children: three case reports and recommendations for care.

    PubMed

    Heller, Felice; Dabaj, Ivana; Mah, Jean K; Bergounioux, Jean; Essid, Aben; Bönnemann, Carsten G; Rutkowski, Anne; Bonne, Gisèle; Quijano-Roy, Susana; Wahbi, Karim

    2016-12-12

    Skeletal and cardiac muscle laminopathies, caused by mutations in the lamin A/C gene, have a clinical spectrum from congenital LMNA-related muscular dystrophy to later-onset Emery-Dreifuss muscular dystrophy, limb girdle muscular dystrophy, and dilated cardiomyopathy. Although cardiac involvement is observed at all ages, it has only been well described in adults. We present the evolution of cardiac disease in three children with congenital muscular dystrophy presentation of LMNA-related muscular dystrophy. In this series, atrial arrhythmia was the presenting cardiac finding in all three patients. Heart failure developed up to 5 years later. Symptoms of right heart failure, including diarrhoea and peripheral oedema, preceded a rapid decline in left ventricular ejection fraction. Recommendations for cardiac surveillance and management in these patients are made.

  14. Dropped head congenital muscular dystrophy caused by de novo mutations in LMNA.

    PubMed

    Karaoglu, Pakize; Quizon, Nicolas; Pergande, Matthias; Wang, Haicui; Polat, Ayşe Ipek; Ersen, Ayca; Özer, Erdener; Willkomm, Lena; Hiz Kurul, Semra; Heredia, Raúl; Yis, Uluç; Selcen, Duygu; Çirak, Sebahattin

    2017-04-01

    Dropped head syndrome is an easily recognizable clinical presentation of Lamin A/C-related congenital muscular dystrophy. Patients usually present in the first year of life with profound neck muscle weakness, dropped head, and elevated serum creatine kinase. Two patients exhibited head drop during infancy although they were able to sit independently. Later they developed progressive axial and limb-girdle weakness. Creatine kinase levels were elevated and muscle biopsies of both patients showed severe dystrophic changes. The distinctive clinical hallmark of the dropped head led us to the diagnosis of Lamin A/C-related congenital muscular dystrophy, with a pathogenic de novo mutation p.Glu31del in the head domain of the Lamin A/C gene in both patients. Remarkably, one patient also had a central involvement with white matter changes on brain magnetic resonance imaging. Lamin A/C-related dropped-head syndrome is a rapidly progressive congenital muscular dystrophy and may lead to loss of ambulation, respiratory insufficiency, and cardiac complications. Thus, the genetic diagnosis of dropped-head syndrome as L-CMD and the implicated clinical care protocols are of vital importance for these patients. This disease may be underdiagnosed, as only a few genetically confirmed cases have been reported. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  15. Merosin-deficient congenital muscular dystrophy (MDCMD): a case report with MRI, MRS and DTI findings.

    PubMed

    Ip, Janice J K; Hui, Peter K T; Chau, M T; Lam, Wendy W M

    2012-08-01

    Congenital muscular dystrophy (CMD) comprises a heterogeneous group of disorders present at birth with muscle weakness, hypotonia and contractures. Congenital muscular dystrophy (CMD) comprises a heterogeneous group of disorders with muscle weakness, hypotonia and contractures present at birth. A particular subset of classic CMD is characterized by a complete absence of merosin. Merosin-deficient congenital muscular dystrophy (MDCMD) is a rare genetic disease involving the central and peripheral nervous system in the childhood. High signal intensities are often observed throughout the centrum semiovale, periventricular, and sub-cortical white matters on T2-weighted images in MRI brain in children with MDCMD. Apparent diffusion coefficient (ADC) map may reveal increased signal intensity and apparent diffusion coefficient values in the periventricular and deep white matters. These white matter findings, observed in late infancy, decrease in severity with age. The pathogenesis of these changes remains uncertain at present. In this article, we outline the specific MR imaging findings seen in a patient with documented MDCMD and also suggest the causes.

  16. A novel recessive GUCY2D mutation causing cone-rod dystrophy and not Leber's congenital amaurosis.

    PubMed

    Ugur Iseri, Sibel A; Durlu, Yusuf K; Tolun, Aslihan

    2010-10-01

    Cone-rod dystrophies are inherited retinal dystrophies that are characterized by progressive degeneration of cones and rods, causing an early decrease in central visual acuity and colour vision defects, followed by loss of peripheral vision in adolescence or early adult life. Both genetic and clinical heterogeneity are well known. In a family with autosomal recessive cone-rod dystrophy, genetic analyses comprising genome scan with microsatellite markers, fine mapping and candidate gene approach resulted in the identification of a homozygous missense GUCY2D mutation. This is the first GUCY2D mutation associated with autosomal recessive cone-rod dystrophy rather than Leber's congenital amaurosis (LCA), a severe disease leading to childhood blindness. This study hence establishes GUCY2D, which is a common cause for both recessive LCA and dominant cone-rod dystrophy, as a good candidate for autosomal recessive cone-rod dystrophy.

  17. If you build a rare disease registry, will they enroll and will they use it? Methods and data from the National Registry of Myotonic Dystrophy (DM) and Facioscapulohumeral Muscular Dystrophy (FSHD)

    PubMed Central

    Hilbert, James E.; Kissel, John T.; Luebbe, Elizabeth A.; Martens, William B.; McDermott, Michael P.; Sanders, Donald B.; Tawil, Rabi; Thornton, Charles A.; Moxley, Richard T.

    2011-01-01

    Introduction Registries are becoming increasingly important for rare diseases as experimental therapies develop. This report describes the methodology behind the National Registry of Myotonic Dystrophy (DM) and Facioscapulohumeral Muscular Dystrophy (FSHD) Patients and Family Members to facilitate the development of other rare disease registries. We also highlight data about the pathophysiology and select burdens of DM and FSHD reported at baseline and longitudinally. Methods The Registry consists of de-identified, patient reported information collected at baseline and annually and information from review of medical records. Investigators can use the Registry to analyze de-identified data and to facilitate recruitment into clinical studies. Results To date, the Registry has enrolled 1611 members, facilitated 24 studies, and collected data annually for up to 8 years. Genetic test results were obtained in 56.2% of enrollees. Approximately one-third of members used assistive devices and another one-third reported psychological problems at baseline. Wheelchair use was reported for both short and long distances by 7.0% of DM and 18.1% of FSHD members. Approximately 60% of members reported their employment was affected by their disease. Conclusions Strengths of the Registry include large sample sizes, stringent review of clinical and molecular data, annually updated information, and regular interactions between patients and investigators. Registry data provide new insights into the burdens of DM and FSHD, such as, psychological problems and reduced employment. Opportunities abound for investigators to utilize Registry resources to assess the impact of these and other burdens on health care costs, progression of symptoms, and quality of life. PMID:22155025

  18. Congenital muscular dystrophy phenotype with neuromuscular spindles excess in a 5-year-old girl caused by HRAS mutation.

    PubMed

    Bolocan, Anamaria; Quijano-Roy, Susana; Seferian, Andreea M; Baumann, Clarisse; Allamand, Valérie; Richard, Pascale; Estournet, Brigitte; Carlier, Robert; Cavé, Hélène; Gartioux, Corine; Blin, Nathalie; Le Moing, Anne-Gaëlle; Gidaro, Teresa; Germain, Dominique P; Fardeau, Michel; Voit, Thomas; Servais, Laurent; Romero, Norma Beatriz

    2014-11-01

    We report on a 5-year-old girl who presented with an association of symptoms reminiscent of an Ullrich-like congenital muscular dystrophy including congenital hypotonia, proximal joint contractures, hyperlaxity of distal joints, normal cognitive development, and kyphoscoliosis. There was an excess of neuromuscular spindles on the skeletal muscle biopsy. This very peculiar feature on muscle biopsy has been reported only in patients with mutations in the HRAS gene. Sequence analysis of the subject's HRAS gene from blood leukocytes and skeletal muscle revealed a previously described heterozygous missense mutation (c.187G>A, p. Glu63Lys). The present report thus extends the differential diagnosis of congenital muscular dystrophy with major "retractile" phenotypes and adds congenital muscular dystrophy to the clinical spectrum of HRAS-related disorders. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Is one trial enough for repeated testing? Same-day assessments of walking, mobility and fine hand use in people with myotonic dystrophy type 1.

    PubMed

    Kierkegaard, Marie; Petitclerc, Emilie; Hébert, Luc J; Gagnon, Cynthia

    2017-02-01

    Performance-based assessments of physical function are essential in people with myotonic dystrophy type 1 (DM1) to monitor disease progression and evaluate interventions. Commonly used are the six-minute walk test, the 10 m-walk test, the timed up-and-go test, the timed-stands test, grip strength tests and the nine-hole peg test. The number of trials needed on a same-day test occasion and whether the first, best or average of trials should be reported as result is unknown. Thus, the aim was to describe and explore differences between trials in these measures of walking, mobility and fine hand use in 70 adults with DM1. Three trials were performed for each test except for the six-minute walk test where two trials were allowed. There were statistical significant differences over trials in all tests except for the 10 m-walk test and grip strength tests. Pair-wise comparisons showed that the second and third trials were in general better than the first, although effect sizes were small. At which trial the individuals performed their best differed between individuals and tests. People with severe muscular impairment had difficulties to perform repeated trials. Intraclass correlation coefficients were all high in analyses exploring how to report results. The conclusion and clinical implication is that, for a same-day test occasion, one trial is sufficient for the 10 m-walk test and grip strength tests, and that repeated trials should be allowed in the timed up-and-go test, timed-stands test and nine-hole peg tests. We recommend that two trials are performed for these latter tests as such a protocol could accommodate people with various levels of impairments and physical limitations.

  20. Incidence and predictors of sudden death, major conduction defects and sustained ventricular tachyarrhythmias in 1388 patients with myotonic dystrophy type 1.

    PubMed

    Wahbi, Karim; Babuty, Dominique; Probst, Vincent; Wissocque, Ludivine; Labombarda, Fabien; Porcher, Raphaël; Bécane, Henri Marc; Lazarus, Arnaud; Béhin, Anthony; Laforêt, Pascal; Stojkovic, Tanya; Clementy, Nicolas; Dussauge, Aurélie Pattier; Gourraud, Jean Baptiste; Pereon, Yann; Lacour, Arnaud; Chapon, Françoise; Milliez, Paul; Klug, Didier; Eymard, Bruno; Duboc, Denis

    2017-03-07

    To describe the incidence and identify predictors of sudden death (SD), major conduction defects and sustained ventricular tachyarrhythmias (VTA) in myotonic dystrophy type 1 (DM1). We retrospectively enrolled 1388 adults with DM1 referred to six French medical centres between January 2000 and October 2013. We confirmed their vital status, classified all deaths, and determined the incidence of major conduction defects requiring permanent pacing and sustained VTA. We searched for predictors of overall survival, SD, major conduction defects, and sustained VTA by Cox regression analysis. Over a median 10-year follow-up, 253 (18.2%) patients died, 39 (3.6%) suddenly. Analysis of the cardiac rhythm at the time of the 39 SD revealed sustained VTA in 9, asystole in 5, complete atrioventricular block in 1 and electromechanical dissociation in two patients. Non-cardiac causes were identified in the five patients with SD who underwent autopsies. Major conduction defects developed in 143 (19.3%) and sustained VTA in 26 (2.3%) patients. By Cox regression analysis, age, family history of SD and left bundle branch block were independent predictors of SD, while age, male sex, electrocardiographic conduction abnormalities, syncope, and atrial fibrillation were independent predictors of major conduction defects; non-sustained VTA was the only predictor of sustained VTA. SD was a frequent mode of death in DM1, with multiple mechanisms involved. Major conduction defects were by far more frequent than sustained VTA, whose only independent predictor was a personal history of non-sustained VTA. ClinicalTrials.gov no: NCT01136330.

  1. Gender as a Modifying Factor Influencing Myotonic Dystrophy Type 1 Phenotype Severity and Mortality: A Nationwide Multiple Databases Cross-Sectional Observational Study

    PubMed Central

    Hamroun, Dalil; Varet, Hugo; Fabbro, Marianne; Rougier, Felix; Amarof, Khadija; Arne Bes, Marie-Christine; Bedat-Millet, Anne-Laure; Behin, Anthony; Bellance, Remi; Bouhour, Françoise; Boutte, Celia; Boyer, François; Campana-Salort, Emmanuelle; Chapon, Françoise; Cintas, Pascal; Desnuelle, Claude; Deschamps, Romain; Drouin-Garraud, Valerie; Ferrer, Xavier; Gervais-Bernard, Helene; Ghorab, Karima; Laforet, Pascal; Magot, Armelle; Magy, Laurent; Menard, Dominique; Minot, Marie-Christine; Nadaj-Pakleza, Aleksandra; Pellieux, Sybille; Pereon, Yann; Preudhomme, Marguerite; Pouget, Jean; Sacconi, Sabrina; Sole, Guilhem; Stojkovich, Tanya; Tiffreau, Vincent; Urtizberea, Andoni; Vial, Christophe; Zagnoli, Fabien; Caranhac, Gilbert; Bourlier, Claude; Riviere, Gerard; Geille, Alain; Gherardi, Romain K.; Eymard, Bruno; Puymirat, Jack; Katsahian, Sandrine; Bassez, Guillaume

    2016-01-01

    Background Myotonic Dystrophy type 1 (DM1) is one of the most heterogeneous hereditary disease in terms of age of onset, clinical manifestations, and severity, challenging both medical management and clinical trials. The CTG expansion size is the main factor determining the age of onset although no factor can finely predict phenotype and prognosis. Differences between males and females have not been specifically reported. Our aim is to study gender impact on DM1 phenotype and severity. Methods We first performed cross-sectional analysis of main multiorgan clinical parameters in 1409 adult DM1 patients (>18y) from the DM-Scope nationwide registry and observed different patterns in males and females. Then, we assessed gender impact on social and economic domains using the AFM-Téléthon DM1 survey (n = 970), and morbidity and mortality using the French National Health Service Database (n = 3301). Results Men more frequently had (1) severe muscular disability with marked myotonia, muscle weakness, cardiac, and respiratory involvement; (2) developmental abnormalities with facial dysmorphism and cognitive impairment inferred from low educational levels and work in specialized environments; and (3) lonely life. Alternatively, women more frequently had cataracts, dysphagia, digestive tract dysfunction, incontinence, thyroid disorder and obesity. Most differences were out of proportion to those observed in the general population. Compared to women, males were more affected in their social and economic life. In addition, they were more frequently hospitalized for cardiac problems, and had a higher mortality rate. Conclusion Gender is a previously unrecognized factor influencing DM1 clinical profile and severity of the disease, with worse socio-economic consequences of the disease and higher morbidity and mortality in males. Gender should be considered in the design of both stratified medical management and clinical trials. PMID:26849574

  2. Instability of the expanded (CTG){sub n} repeats in the myotonin protein kinase gene in cultured lymphoblastoid cell lines from patients with myotonic dystrophy

    SciTech Connect

    Ashizawa, Tetsuo; Patel, B.J.; Monckton, D.G.

    1996-08-15

    The mutation associated with myotonic dystrophy (DM) is the expansion of an unstable trinucleotide repeat, (CTG){sub n}, in the 3{prime}-untranslated region of the myotonin protein kinase gene. Although expanded repeats show both germline and somatic instability, the mechanisms of the instability are poorly understood. To establish a model system in which somatic instability of the DM repeat could be studied in more detail, we established lymphoblastoid cell lines (LBCL) from DM patients. Analysis of the DNA from DM LBCL using Southern blotting showed that the (CTG). repeats were apparently stable up to 29 passages in culture. To study infrequent repeat size mutations that are undetectable due to the size heterogeneity, we established LBCL of single-cell origins by cloning using multiple steps of limiting dilution. After expansion to approximately 10{sup 6} cells (equivalent to approximately 20 cell cycles), the DNAs of these cell lines were analyzed by the small pool PCR technique using primers flanking the (CTG), repeat region. Two types of mutations of the expanded (CTG){sub n} repeat alleles were detected: (1) frequent mutations that show small changes of the (CTG){sub n} repeat size, resulting in alleles in a normal distribution around the progenitor allele, and (2) relatively rare mutations with large changes of the (CTG){sub n} repeat size, with a bias toward contraction. The former may represent the mechanism responsible for the so matic heterogeneity of the (CTG), repeat size observe in blood cells of DM patients. This in vitro experimental system will be useful for further studies on mechanisms involved in the regulation of the somatic stability of the (CTG). repeats in DM. 24 refs., 4 figs.

  3. Genome modification leads to phenotype reversal in human myotonic dystrophy type 1 induced pluripotent stem cell-derived neural stem cells.

    PubMed

    Xia, Guangbin; Gao, Yuanzheng; Jin, Shouguang; Subramony, S H; Terada, Naohiro; Ranum, Laura P W; Swanson, Maurice S; Ashizawa, Tetsuo

    2015-06-01

    Myotonic dystrophy type 1 (DM1) is caused by expanded CTG repeats in the 3'-untranslated region (3' UTR) of the DMPK gene. Correcting the mutation in DM1 stem cells would be an important step toward autologous stem cell therapy. The objective of this study is to demonstrate in vitro genome editing to prevent production of toxic mutant transcripts and reverse phenotypes in DM1 stem cells. Genome editing was performed in DM1 neural stem cells (NSCs) derived from human DM1 induced pluripotent stem (iPS) cells. An editing cassette containing SV40/bGH polyA signals was integrated upstream of the CTG repeats by TALEN-mediated homologous recombination (HR). The expression of mutant CUG repeats transcript was monitored by nuclear RNA foci, the molecular hallmarks of DM1, using RNA fluorescence in situ hybridization. Alternative splicing of microtubule-associated protein tau (MAPT) and muscleblind-like (MBNL) proteins were analyzed to further monitor the phenotype reversal after genome modification. The cassette was successfully inserted into DMPK intron 9 and this genomic modification led to complete disappearance of nuclear RNA foci. MAPT and MBNL 1, 2 aberrant splicing in DM1 NSCs were reversed to normal pattern in genome-modified NSCs. Genome modification by integration of exogenous polyA signals upstream of the DMPK CTG repeat expansion prevents the production of toxic RNA and leads to phenotype reversal in human DM1 iPS-cells derived stem cells. Our data provide proof-of-principle evidence that genome modification may be used to generate genetically modified progenitor cells as a first step toward autologous cell transfer therapy for DM1.

  4. Elevated plasma levels of cardiac troponin-I predict left ventricular systolic dysfunction in patients with myotonic dystrophy type 1: A multicentre cohort follow-up study

    PubMed Central

    Robb, Yvonne; Cumming, Sarah; Gregory, Helen; Duncan, Alexis; Rahman, Monika; McKeown, Anne; McWilliam, Catherine; Dean, John; Wilcox, Alison; Farrugia, Maria E.; Cooper, Anneli; McGhie, Josephine; Adam, Berit; Petty, Richard; Longman, Cheryl; Findlay, Iain; Japp, Alan; Monckton, Darren G.; Denvir, Martin A.

    2017-01-01

    Objective High sensitivity plasma cardiac troponin-I (cTnI) is emerging as a strong predictor of cardiac events in a variety of settings. We have explored its utility in patients with myotonic dystrophy type 1 (DM1). Methods 117 patients with DM1 were recruited from routine outpatient clinics across three health boards. A single measurement of cTnI was made using the ARCHITECT STAT Troponin I assay. Demographic, ECG, echocardiographic and other clinical data were obtained from electronic medical records. Follow up was for a mean of 23 months. Results Fifty five females and 62 males (mean age 47.7 years) were included. Complete data were available for ECG in 107, echocardiography in 53. Muscle Impairment Rating Scale score was recorded for all patients. A highly significant excess (p = 0.0007) of DM1 patients presented with cTnI levels greater than the 99th centile of the range usually observed in the general population (9 patients; 7.6%). Three patients with elevated troponin were found to have left ventricular systolic dysfunction (LVSD), compared with four of those with normal range cTnI (33.3% versus 3.7%; p = 0.001). Sixty two patients had a cTnI level < 5ng/L, of whom only one had documented evidence of LVSD. Elevated cTnI was not predictive of severe conduction abnormalities on ECG, or presence of a cardiac device, nor did cTnI level correlate with muscle strength expressed by Muscle Impairment Rating Scale score. Conclusions Plasma cTnI is highly elevated in some ambulatory patients with DM1 and shows promise as a tool to aid cardiac risk stratification, possibly by detecting myocardial involvement. Further studies with larger patient numbers are warranted to assess its utility in this setting. PMID:28323905

  5. Design of a bioactive small molecule that targets the myotonic dystrophy type 1 RNA via an RNA motif-ligand database and chemical similarity searching.

    PubMed

    Parkesh, Raman; Childs-Disney, Jessica L; Nakamori, Masayuki; Kumar, Amit; Wang, Eric; Wang, Thomas; Hoskins, Jason; Tran, Tuan; Housman, David; Thornton, Charles A; Disney, Matthew D

    2012-03-14

    Myotonic dystrophy type 1 (DM1) is a triplet repeating disorder caused by expanded CTG repeats in the 3'-untranslated region of the dystrophia myotonica protein kinase (DMPK) gene. The transcribed repeats fold into an RNA hairpin with multiple copies of a 5'CUG/3'GUC motif that binds the RNA splicing regulator muscleblind-like 1 protein (MBNL1). Sequestration of MBNL1 by expanded r(CUG) repeats causes splicing defects in a subset of pre-mRNAs including the insulin receptor, the muscle-specific chloride ion channel, sarco(endo)plasmic reticulum Ca(2+) ATPase 1, and cardiac troponin T. Based on these observations, the development of small-molecule ligands that target specifically expanded DM1 repeats could be of use as therapeutics. In the present study, chemical similarity searching was employed to improve the efficacy of pentamidine and Hoechst 33258 ligands that have been shown previously to target the DM1 triplet repeat. A series of in vitro inhibitors of the RNA-protein complex were identified with low micromolar IC(50)'s, which are >20-fold more potent than the query compounds. Importantly, a bis-benzimidazole identified from the Hoechst query improves DM1-associated pre-mRNA splicing defects in cell and mouse models of DM1 (when dosed with 1 mM and 100 mg/kg, respectively). Since Hoechst 33258 was identified as a DM1 binder through analysis of an RNA motif-ligand database, these studies suggest that lead ligands targeting RNA with improved biological activity can be identified by using a synergistic approach that combines analysis of known RNA-ligand interactions with chemical similarity searching.

  6. Congenital disorder of glycosylation due to DPM1 mutations presenting with dystroglycanopathy-type congenital muscular dystrophy

    PubMed Central

    Moore, Steven A.; Rush, Jeffrey; Waechter, Charles J.; Raymond, Kimiyo M.; Willer, Tobias; Campbell, Kevin P.; Freeze, Hudson H.; Mehta, Lakshmi

    2013-01-01

    Congenital disorders of glycosylation (CDG) are rare genetic defects mainly in the post-translational modification of proteins via attachment of carbohydrate chains. We describe an infant with the phenotype of a congenital muscular dystrophy, with borderline microcephaly, hypotonia, camptodactyly, severe motor delay, and elevated creatine kinase. Muscle biopsy showed muscular dystrophy and reduced α-dystroglycan immunostaining with glycoepitope-specific antibodies in a pattern diagnostic of dystroglycanopathy. Carbohydrate deficient transferrin testing showed a pattern pointing to a CDG type I. Sanger sequencing of DPM1 (dolichol-P-mannose synthase subunit 1) revealed a novel Gly>Val change c.455 G>T missense mutation resulting in p.Gly152Val) of unknown pathogenicity and deletion/duplication analysis revealed an intragenic deletion from exons 3 to 7 on the other allele. DPM1 activity in fibroblasts was reduced by 80%, while affinity for the substrate was not depressed, suggesting a decrease in the amount of active enzyme. Transfected cells expressing tagged versions of wild type and the p.Gly152Val mutant displayed reduced binding to DPM3, an essential, non-catalytic subunit of the DPM complex, suggesting a mechanism for pathogenicity. The present case is the first individual described with DPM1-CDG (CDG-Ie) to also have clinical and muscle biopsy findings consistent with dystroglycanopathy. PMID:23856421

  7. Congenital disorder of glycosylation due to DPM1 mutations presenting with dystroglycanopathy-type congenital muscular dystrophy.

    PubMed

    Yang, Amy C; Ng, Bobby G; Moore, Steven A; Rush, Jeffrey; Waechter, Charles J; Raymond, Kimiyo M; Willer, Tobias; Campbell, Kevin P; Freeze, Hudson H; Mehta, Lakshmi

    2013-11-01

    Congenital disorders of glycosylation (CDG) are rare genetic defects mainly in the post-translational modification of proteins via attachment of carbohydrate chains. We describe an infant with the phenotype of a congenital muscular dystrophy, with borderline microcephaly, hypotonia, camptodactyly, severe motor delay, and elevated creatine kinase. Muscle biopsy showed muscular dystrophy and reduced α-dystroglycan immunostaining with glycoepitope-specific antibodies in a pattern diagnostic of dystroglycanopathy. Carbohydrate deficient transferrin testing showed a pattern pointing to a CDG type I. Sanger sequencing of DPM1 (dolichol-P-mannose synthase subunit 1) revealed a novel Gly > Val change c.455G > T missense mutation resulting in p.Gly152Val) of unknown pathogenicity and deletion/duplication analysis revealed an intragenic deletion from exons 3 to 7 on the other allele. DPM1 activity in fibroblasts was reduced by 80%, while affinity for the substrate was not depressed, suggesting a decrease in the amount of active enzyme. Transfected cells expressing tagged versions of wild type and the p.Gly152Val mutant displayed reduced binding to DPM3, an essential, non-catalytic subunit of the DPM complex, suggesting a mechanism for pathogenicity. The present case is the first individual described with DPM1-CDG (CDG-Ie) to also have clinical and muscle biopsy findings consistent with dystroglycanopathy. © 2013 Elsevier Inc. All rights reserved.

  8. ISPD gene mutations are a common cause of congenital and limb-girdle muscular dystrophies.

    PubMed

    Cirak, Sebahattin; Foley, Aileen Reghan; Herrmann, Ralf; Willer, Tobias; Yau, Shu; Stevens, Elizabeth; Torelli, Silvia; Brodd, Lina; Kamynina, Alisa; Vondracek, Petr; Roper, Helen; Longman, Cheryl; Korinthenberg, Rudolf; Marrosu, Gianni; Nürnberg, Peter; Michele, Daniel E; Plagnol, Vincent; Hurles, Matt; Moore, Steven A; Sewry, Caroline A; Campbell, Kevin P; Voit, Thomas; Muntoni, Francesco

    2013-01-01

    Dystroglycanopathies are a clinically and genetically diverse group of recessively inherited conditions ranging from the most severe of the congenital muscular dystrophies, Walker-Warburg syndrome, to mild forms of adult-onset limb-girdle muscular dystrophy. Their hallmark is a reduction in the functional glycosylation of α-dystroglycan, which can be detected in muscle biopsies. An important part of this glycosylation is a unique O-mannosylation, essential for the interaction of α-dystroglycan with extracellular matrix proteins such as laminin-α2. Mutations in eight genes coding for proteins in the glycosylation pathway are responsible for ∼50% of dystroglycanopathy cases. Despite multiple efforts using traditional positional cloning, the causative genes for unsolved dystroglycanopathy cases have escaped discovery for several years. In a recent collaborative study, we discovered that loss-of-function recessive mutations in a novel gene, called isoprenoid synthase domain containing (ISPD), are a relatively common cause of Walker-Warburg syndrome. In this article, we report the involvement of the ISPD gene in milder dystroglycanopathy phenotypes ranging from congenital muscular dystrophy to limb-girdle muscular dystrophy and identified allelic ISPD variants in nine cases belonging to seven families. In two ambulant cases, there was evidence of structural brain involvement, whereas in seven, the clinical manifestation was restricted to a dystrophic skeletal muscle phenotype. Although the function of ISPD in mammals is not yet known, mutations in this gene clearly lead to a reduction in the functional glycosylation of α-dystroglycan, which not only causes the severe Walker-Warburg syndrome but is also a common cause of the milder forms of dystroglycanopathy.

  9. [Congenital muscular dystrophy with laminin-a2 deficiency in early infancy: diagnosis and long-term follow-up].

    PubMed

    Panteliadis, C; Karatza, E; Xinias, I; Flaris, N; Tzitiridou, M; Ramantani, G

    2005-01-01

    Congenital muscular dystrophy (CMD) is a heterogeneous group of neuromuscular disorders characterized by muscle weakness and hypotonia at birth or within the first few months of life. It is inherited in an autosomal recessive pattern. About half of the patients have a deficiency of the alpha-2-chain of laminin (merosin). We describe a case of congenital muscular dystrophy in an infant with laminin-a2-chain deficiency, which appeared hypotonia in early infancy. Diagnosis was made by clinical features and the histological and immunohistochemical studies on muscle biopsy.

  10. Three-dimensional MR imaging of brain surface anomalies in Fukuyama-type congenital muscular dystrophy.

    PubMed

    Toda, T; Watanabe, T; Matsumura, K; Sunada, Y; Yamada, H; Nakano, I; Mannen, T; Kanazawa, I; Shimizu, T

    1995-05-01

    Fukuyama-type congenital muscular dystrophy (FCMD), the second most common childhood muscular dystrophy in Japan, is characterized by the association with severe brain anomalies such as pachygyria and focal interhemispheric fusion. Conventional imaging techniques such as X-ray CT scan and MRI are ineffective for visualization of these brain surface anomalies. Here we investigated the efficacy of three-dimensional (3-D) reconstruction of brain surface MR images for the detection of brain anomalies in FCMD patients. 3-D brain surface MR images clearly visualized anomalies of cerebral gyrus such as pachygyria, as well as focal interhemispheric fusion. In addition, reconstructed horizontal images visualized structural derangement such as abnormal protrusion of white matter into gray matter. MR image abnormalities were confirmed by autopsy in 1 patient. These abnormalities were never observed in Duchenne muscular dystrophy (DMD) patients. Our results indicate the efficacy of the present method for the differential diagnosis between FCMD and DMD with severe mental retardation, which is essential for the genetic study to identify the causative gene of FCMD.

  11. [Merosin-positive congenital muscular dystrophy with early orthopaedic problems in relation to Ullrich's disease].

    PubMed

    Chang, Sangmi; Ishikawa, Tatsuya; Nonaka, Ikuya; Tsukamoto, Haruko; Saito, Mariko; Ban, Kyoko; Wada, Ikuo; Sugie, Kazuma; Nishino, Ichizo

    2003-03-01

    We report three patients with sporadic merosin-positive congenital muscular dystrophy (CMD) with torticollis and/or developmental dislocation of the hip in early childhood. Diagnosis of merosin-positive CMD was based on their clinical and dystrophic muscle biopsy findings. At the age 13 months, patient 1 was found to have developmental dislocation of both hips, which was surgically treated at 5 years. Patient 2 had severe torticollis and contracture of both hip joints which had been present since the neonatal period, and underwent repair of the torticollis at 2 years. Patient 3 was found to have developmental dislocation of the left hip at one month of age. Although she had generalized muscle hypotonia she learned to walk at 23 months. She had no facial muscle involvement nor contracture of joints, but had hyperlaxity of distal joints. Her muscle biopsy showed complete collagen VI deficiency immunohistochemically. In contrast to merosin-deficient CMD, merosin-positive CMD appears to be a group of heterogeneous diseases. Since collagen VI was reported to be defective in Ullrich's disease, patient 3 may be diagnosed as having Ullrich's disease but had no typical clinical characteristics of the disease. Further study is needed to identify the pathogenetic mechanism of congenital muscular dystrophy with early joint abnormalities to determine whether there is a primary abnormality of the connective tissue including collagen VI.

  12. Cortical and Subcortical Grey and White Matter Atrophy in Myotonic Dystrophies Type 1 and 2 Is Associated with Cognitive Impairment, Depression and Daytime Sleepiness

    PubMed Central

    Prehn, Christian; Krogias, Christos; Schneider, Ruth; Klein, Jan; Gold, Ralf; Lukas, Carsten

    2015-01-01

    Objectives Central nervous system involvement is one important clinical aspect of myotonic dystrophy type 1 and 2 (DM1 and DM2). We assessed CNS involvement DM1 and DM2 by 3T MRI and correlated clinical and neuocognitive symptoms with brain volumetry and voxel-based morphometry (VBM). Methods 12 patients with juvenile or classical DM1 and 16 adult DM2 patients underwent 3T MRI, a thorough neurological and neuropsychological examination and scoring of depression and daytime sleepiness. Volumes of brain, ventricles, cerebellum, brainstem, cervical cord, lesion load and VBM results of the patient groups were compared to 33 matched healthy subjects. Results Clinical symptoms were depression (more pronounced in DM2), excessive daytime sleepiness (more pronounced in DM1), reduced attention and flexibility of thinking, and deficits of short-term memory and visuo-spatial abilities in both patient groups. Both groups showed ventricular enlargement and supratentorial GM and WM atrophy, with prevalence for more GM atrophy and involvement of the motor system in DM1 and more WM reduction and affection of limbic structures in DM2. White matter was reduced in DM1 in the splenium of the corpus callosum and in left-hemispheric WM adjacent to the pre- and post-central gyrus. In DM2, the bilateral cingulate gyrus and subgyral medio-frontal and primary somato-sensory WM was affected. Significant structural-functional correlations of morphological MRI findings (global volumetry and VBM) with clinical findings were found for reduced flexibility of thinking and atrophy of the left secondary visual cortex in DM1 and of distinct subcortical brain structures in DM2. In DM2, depression was associated with brainstem atrophy, Daytime sleepiness correlated with volume decrease in the middle cerebellar peduncles, pons/midbrain and the right medio-frontal cortex. Conclusion GM and WM atrophy was significant in DM1 and DM2. Specific functional-structural associations related morphological changes

  13. Analysis of CTG repeat length variation in the DMPK gene in the general population and the molecular diagnosis of myotonic dystrophy type 1 in Malaysia.

    PubMed

    Ambrose, Kathlin K; Ishak, Taufik; Lian, Lay-Hoong; Goh, Khean-Jin; Wong, Kum-Thong; Ahmad-Annuar, Azlina; Thong, Meow-Keong

    2017-03-31

    The lack of epidemiological data and molecular diagnostic services in Malaysia has hampered the setting-up of a comprehensive management plan for patients with myotonic dystrophy type 1 (DM1), leading to delayed diagnosis, treatment and support for patients and families. The aim of this study was to estimate the prevalence of DM1 in the 3 major ethnic groups in Malaysia and evaluate the feasibility of a single tube triplet-primed PCR (TP-PCR) method for diagnosis of DM1 in Malaysia. We used PCR to determine the size of CTG repeats in 377 individuals not known to be affected by DM and 11 DM1 suspected patients, recruited from a tertiary hospital in Kuala Lumpur. TP-PCR was performed on selected samples, followed by Southern blot hybridisation of PCR amplified fragments to confirm and estimate the size of CTG expansion. The number of individuals not known to be affected by DM with (CTG)>18 was determined according to ethnic group and as a whole population. The χ(2) test was performed to compare the distribution of (CTG)>18 with 12 other populations. Additionally, the accuracy of TP-PCR in detecting CTG expansion in 11 patients with DM1 was determined by comparing the results with that from Southern blot hybridisation. Of the 754 chromosomes studied, (CTG)>18 frequency of 3.60%, 1.57% and 4.00% in the Malay, Chinese and Indian subpopulations, respectively, was detected, showing similarities to data from Thai, Taiwanese and Kuwaiti populations. We also successfully detected CTG expansions in 9 patients using the TP-PCR method followed by the estimation of CTG expansion size via Southern blot hybridisation. The results show a low DM1 prevalence in Malaysia with the possibility of underdiagnosis and demonstrates the feasibility of using a clinical and TP-PCR-based approach for rapid and cost-effective DM1 diagnosis in developing countries. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  14. Rational design of ligands targeting triplet repeating transcripts that cause RNA dominant disease: application to myotonic muscular dystrophy type 1 and spinocerebellar ataxia type 3.

    PubMed

    Pushechnikov, Alexei; Lee, Melissa M; Childs-Disney, Jessica L; Sobczak, Krzysztof; French, Jonathan M; Thornton, Charles A; Disney, Matthew D

    2009-07-22

    Herein, we describe the design of high affinity ligands that bind expanded rCUG and rCAG repeat RNAs expressed in myotonic dystrophy type 1 (DM1) and spinocerebellar ataxia type 3. These ligands also inhibit, with nanomolar IC(50) values, the formation of RNA-protein complexes that are implicated in both disorders. The expanded rCUG and rCAG repeats form stable RNA hairpins with regularly repeating internal loops in the stem and have deleterious effects on cell function. The ligands that bind the repeats display a derivative of the bisbenzimidazole Hoechst 33258, which was identified by searching known RNA-ligand interactions for ligands that bind the internal loop displayed in these hairpins. A series of 13 modularly assembled ligands with defined valencies and distances between ligand modules was synthesized to target multiple motifs in these RNAs simultaneously. The most avid binder, a pentamer, binds the rCUG repeat hairpin with a K(d) of 13 nM. When compared to a series of related RNAs, the pentamer binds to rCUG repeats with 4.4- to >200-fold specificity. Furthermore, the affinity of binding to rCUG repeats shows incremental gains with increasing valency, while the background binding to genomic DNA is correspondingly reduced. Then, it was determined whether the modularly assembled ligands inhibit the recognition of RNA repeats by Muscleblind-like 1 (MBNL1) protein, the expanded-rCUG binding protein whose sequestration leads to splicing defects in DM1. Among several compounds with nanomolar IC(50) values, the most potent inhibitor is the pentamer, which also inhibits the formation of rCAG repeat-MBNL1 complexes. Comparison of the binding data for the designed synthetic ligands and MBNL1 to repeating RNAs shows that the synthetic ligand is 23-fold higher affinity and more specific to DM1 RNAs than MBNL1. Further studies show that the designed ligands are cell permeable to mouse myoblasts. Thus, cell permeable ligands that bind repetitive RNAs have been designed

  15. Abnormal calcium metabolism in myotonic dystrophy as shown by the Ellsworth-Howard test and its relation to CTG triplet repeat length.

    PubMed

    Kinoshita, M; Komori, T; Ohtake, T; Takahashi, R; Nagasawa, R; Hirose, K

    1997-10-01

    Myotonic dystrophy (DM) is an autosomal dominant disorder characterized by peculiar clinical features. Its molecular basis is the unstable expansion of a CTG triplet repeat in the gene encoding myotonin protein kinase (Mt-PK), the nucleotide sequence of which has extensive homology to the cyclic AMP (cAMP)-dependent protein kinase gene. Extensive efforts have been made to clarify the signal transduction pathway in which the responsible gene operates, but confirming evidence has yet to be obtained. Because some symptoms in DM are similar to those in hypoparathyroidism, we divided 24 DM patients into two groups on the basis of their serum calcium levels; Group 1, those with normocalcemia (11 patients), and group 2, those with hypocalcemia (13 patients). The highly sensitive parathyroid hormone (HS-PTH) plasma levels in group 1 were within normal limits, whereas those in group 2 were abnormally high. Laboratory findings for the group 2 patients resembled those for pseudohypoparathyroidism (PHP), whereas those for group 1 patients were normal. The Ellsworth-Howard (EH) test was used to determine which type of PHP the group 2 patients belonged to. Both the phosphaturic (delta P) and urinary cAMP (UcAMP) responses were estimated. The delta P responses in group 2 were significantly lower than those in group 1, but their UcAMP responses did not differ. This is evidence that group 2 patients had PHP type II, whereas group 1 patients were normal. We also investigated whether the disease severity differed between the groups. Cataracts, ectopic calcifications, and ossifications, which are associated with PHP, were more frequent in group 2. In addition, the mean IQ in that group was significantly lower. Clinically, the group 2 signs agreed well with those of PHP, whereas for group 1 there was only a slight similarity. These results are additional evidence that the patients in group 2 have abnormal calcium metabolism, the abnormality being in the postadenylate cyclase

  16. Ullrich Congenital Muscular Dystrophy Possibly Related With COL6A1 p.Gly302Arg Variant.

    PubMed

    Park, Yoonhong; Park, Myung Seok; Sung, Duk Hyun; Sohn, Ji Yeon; Ki, Chang-Seok; Kim, Du-Hwan

    2014-04-01

    Ullrich congenital muscular dystrophy (UCMD) is characterized by congenital weakness, proximal joint contractures, and hyperlaxity of distal joints. UCMD is basically due to a defect in extra cellular matrix protein, collagen type VI. A 37-year-old woman who cannot walk independently visited our outpatient clinic. She had orthopedic deformities (scoliosis, joint contractures, and distal joint hyperlaxity), difficulty of respiration, and many skin keloids. Her hip computed tomography showed diffuse fatty infiltration and the 'central shadow' sign in thigh muscles. From the clinical information suggesting collagen type VI related muscle disorder, UCMD was highly considered. COL6A1 gene sequencing confirmed this patient as UCMD with novel c.904G>A (p.Gly302Arg) variant. If musculoskeletal and dermatologic manifestations and radiologic findings imply abnormalities in collagen type VI network, COL6A related congenital muscular dystrophy was to be suspected.

  17. Reduced expression of sarcospan in muscles of Fukuyama congenital muscular dystrophy.

    PubMed

    Wakayama, Yoshihiro; Inoue, Masahiko; Kojima, Hiroko; Yamashita, Sumimasa; Shibuya, Seiji; Jimi, Takahiro; Hara, Hajime; Matsuzaki, Yoko; Oniki, Hiroaki; Kanagawa, Motoi; Kobayashi, Kazuhiro; Toda, Tatsushi

    2008-12-01

    Expression profiles of sarcospan in muscles with muscular dystrophies are scarcely reported. To examine this, we studied five Fukuyama congenital muscular dystrophy (FCMD) muscles, five Duchenne muscular dystrophy (DMD) muscles, five disease control and five normal control muscles. Immunoblot showed reactions of sarcospan markedly decreased in FCMD and DMD muscle extracts. Immunohistochemistry of FCMD muscles showed that most large diameter myofibers expressed sarcospan discontinuously at their surface membranes. Immature small diameter FCMD myofibers usually did not express sarcospan. Immunoreactivity of sarcospan in DMD muscles was similarly reduced. With regard to dystroglycans and sarcoglycans, immunohistochemistry of FCMD muscles showed selective deficiency of glycosylated alpha-dystroglycan, together with reduced expression of beta-dystroglycan and alpha-, beta-, gamma-, delta-sarcoglycans. Although the expression of glycosylated alpha-dystroglycan was lost, scattered FCMD myofibers showed positive immunoreaction with an antibody against the core protein of alpha-dystroglycan. The group mean ratios of sarcospan mRNA copy number versus GAPDH mRNA copy number by real-time RT-PCR showed that the ratios between FCMD and normal control groups were not significantly different (P>0.1 by the two-tailed t test). This study implied either O-linked glycosylation defects of alpha-dystroglycan in the Golgi apparatus of FCMD muscles may lead to decreased expression of sarcoglycan and sarcospan molecules, or selective deficiency of glycosylated alpha-dystroglycan due to impaired glycosylation in FCMD muscles may affect the molecular integrity of the basal lamina of myofibers. This, in turn, leads to decreased expression of sarcoglycans, and finally of sarcospan at the FCMD myofiber surfaces.

  18. A novel early onset phenotype in a zebrafish model of merosin deficient congenital muscular dystrophy

    PubMed Central

    Smith, Sarah J.; Wang, Jeffrey C.; Gupta, Vandana A.; Dowling, James J.

    2017-01-01

    Merosin deficient congenital muscular dystrophy (MDC1A) is a severe neuromuscular disorder with onset in infancy that is associated with severe morbidities (particularly wheelchair dependence) and early mortality. It is caused by recessive mutations in the LAMA2 gene that encodes a subunit of the extracellular matrix protein laminin 211. At present, there are no treatments for this disabling disease. The zebrafish has emerged as a powerful model system for the identification of novel therapies. However, drug discovery in the zebrafish is largely dependent on the identification of phenotypes suitable for chemical screening. Our goal in this study was to elucidate novel, early onset abnormalities in the candyfloss (caf) zebrafish, a model of MDC1A. We uncovered and characterize abnormalities in spontaneous coiling, the earliest motor movement in the zebrafish, as a fully penetrant change specific to caf mutants that is ideal for future drug testing. PMID:28241031

  19. Respiratory and cardiac function in congenital muscular dystrophies with alpha dystroglycan deficiency.

    PubMed

    Pane, M; Messina, S; Vasco, G; Foley, A R; Morandi, L; Pegoraro, E; Mongini, T; D'Amico, A; Bianco, F; Lombardo, M E; Scalise, R; Bruno, C; Berardinelli, A; Pini, A; Moroni, I; Mora, M; Toscano, A; Moggio, M; Comi, G; Santorelli, F M; Bertini, E; Muntoni, F; Mercuri, E

    2012-08-01

    The aim of this retrospective study was to assess respiratory and cardiac function in a large cohort of patients with congenital muscular dystrophies (CMD) with reduced glycosylation of alphadystroglycan (α-DG). Thirteen of the 115 patients included in the study died between the age of 1 month and 20 years. The age at last follow up of the surviving 102 ranged between 1 year and 68 years (median: 9.3 years). Cardiac involvement was found in 7 of the 115 (6%), 5 with dilated cardiomyopathy, 1 cardiac conductions defects and 1 mitral regurgitation. Respiratory function was impaired in 14 (12%). Ten of the 14 required non invasive nocturnal respiratory support, while the other four required invasive ventilation. Cardiac or respiratory involvement was found in patients with mutations in FKRP, POMT1, POMT2. All of the patients in whom mutation in POMGnT1 were identified had normal cardiac and respiratory function.

  20. From "glycosyltransferase" to "congenital muscular dystrophy": integrating knowledge from NCBI Entrez Gene and the Gene Ontology.

    PubMed

    Sahoo, Satya S; Zeng, Kelly; Bodenreider, Olivier; Sheth, Amit

    2007-01-01

    Entrez Gene (EG), Online Mendelian Inheritance in Man (OMIM) and the Gene Ontology (GO) are three complementary knowledge resources that can be used to correlate genomic data with disease information. However, bridging between genotype and phenotype through these resources currently requires manual effort or the development of customized software. In this paper, we argue that integrating EG and GO provides a robust and flexible solution to this problem. We demonstrate how the Resource Description Framework (RDF) developed for the Semantic Web can be used to represent and integrate these resources and enable seamless access to them as a unified resource. We illustrate the effectiveness of our approach by answering a real-world biomedical query linking a specific molecular function, glycosyltransferase, to the disorder congenital muscular dystrophy.

  1. Evidence-based guideline summary: Evaluation, diagnosis, and management of congenital muscular dystrophy

    PubMed Central

    Kang, Peter B.; Morrison, Leslie; Iannaccone, Susan T.; Graham, Robert J.; Bönnemann, Carsten G.; Rutkowski, Anne; Hornyak, Joseph; Wang, Ching H.; North, Kathryn; Oskoui, Maryam; Getchius, Thomas S.D.; Cox, Julie A.; Hagen, Erin E.; Gronseth, Gary; Griggs, Robert C.

    2015-01-01

    Objective: To delineate optimal diagnostic and therapeutic approaches to congenital muscular dystrophy (CMD) through a systematic review and analysis of the currently available literature. Methods: Relevant, peer-reviewed research articles were identified using a literature search of the MEDLINE, EMBASE, and Scopus databases. Diagnostic and therapeutic data from these articles were extracted and analyzed in accordance with the American Academy of Neurology classification of evidence schemes for diagnostic, prognostic, and therapeutic studies. Recommendations were linked to the strength of the evidence, other related literature, and general principles of care. Results: The geographic and ethnic backgrounds, clinical features, brain imaging studies, muscle imaging studies, and muscle biopsies of children with suspected CMD help predict subtype-specific diagnoses. Genetic testing can confirm some subtype-specific diagnoses, but not all causative genes for CMD have been described. Seizures and respiratory complications occur in specific subtypes. There is insufficient evidence to determine the efficacy of various treatment interventions to optimize respiratory, orthopedic, and nutritional outcomes, and more data are needed regarding complications. Recommendations: Multidisciplinary care by experienced teams is important for diagnosing and promoting the health of children with CMD. Accurate assessment of clinical presentations and genetic data will help in identifying the correct subtype-specific diagnosis in many cases. Multiorgan system complications occur frequently; surveillance and prompt interventions are likely to be beneficial for affected children. More research is needed to fill gaps in knowledge regarding this category of muscular dystrophies. PMID:25825463

  2. Deficiency of merosin in dystrophic dy mouse homologue of congenital muscular dystrophy

    SciTech Connect

    Sunada, Y.; Campbell, K.P.; Bernier, S.M.

    1994-09-01

    Merosin (laminin M chain) is the predominant laminin isoform in the basal lamina of striated muscle and peripheral nerve and is a native ligand for {alpha}-dystroglycan, a novel laminin receptor. Merosin is linked to the subsarcolemmal actin cytoskeleton via the dystrophin-glycoprotein complex (DGC), which plays an important role for maintenance of normal muscle function. We have mapped the mouse merosin gene, Lamm, to the region containing the dystrophia muscularis (dy) locus on chromosome 10. This suggested the possibility that a mutation in the merosin gene could be responsible for the dy mouse, an animal model for autosomal recessive muscular dystrophy, and prompted us to test this hypothesis. We analyzed the status of merosin expression in dy mouse by immunofluorescence and immunoblotting. In dy mouse skeletal and cardiac muscle and peripheral nerve, merosin was reduced greater than 90% as compared to control mice. However, the expression of laminin B1/B2 chains and collagen type IV was smaller to that in control mice. These findings strongly suggest that merosin deficiency may be the primary defect in the dy mouse. Furthermore, we have identified two patients afflicted with congenital muscular dystrophy with merosin deficiency, providing the basis for future studies of molecular pathogenesis and gene therapy.

  3. Genotype/phenotype analysis in Chinese laminin-α2 deficient congenital muscular dystrophy patients.

    PubMed

    Xiong, H; Tan, D; Wang, S; Song, S; Yang, H; Gao, K; Liu, A; Jiao, H; Mao, B; Ding, J; Chang, X; Wang, J; Wu, Y; Yuan, Y; Jiang, Y; Zhang, F; Wu, H; Wu, X

    2015-03-01

    Laminin-α2 deficient congenital muscular dystrophy (CMD) is an autosomal recessive disorder characterized by severe muscular dystrophy, which is typically associated with abnormal white matter. In this study, we assessed 43 CMD patients with typical white matter abnormality and laminin-α2 deficiency (complete or partial) diagnosed by immunohistochemistry to determine the clinical and molecular genetic characteristics of laminin-α2 deficient CMD. LAMA2 gene mutation analysis was performed by direct sequencing of genomic DNAs. Exonic deletion or duplication was identified by multiplex ligation-dependent probe amplification (MLPA) and verified by high-density oligonucleotide-based CGH microarrays. Gene mutation analysis revealed 86 LAMA2 mutations (100%); 15 known and 37 novel. Among these mutations, 73.9% were nonsense, splice-site or frameshift and 18.8% were deletions of one or more exons. Genetic characterization of affected families will be valuable in prenatal diagnosis of CMD in the Chinese population. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. The gross motor function measure is valid for Fukuyama congenital muscular dystrophy.

    PubMed

    Sato, Takatoshi; Adachi, Michiru; Nakamura, Kaho; Zushi, Masaya; Goto, Keisuke; Murakami, Terumi; Ishiguro, Kumiko; Shichiji, Minobu; Saito, Kayoko; Ikai, Tetsuo; Osawa, Makiko; Kondo, Izumi; Nagata, Satoru; Ishigaki, Keiko

    2017-01-01

    Fukuyama congenital muscular dystrophy (FCMD) is the second most common muscular dystrophy in Japan. FCMD is an autosomal recessive disorder caused by mutations in the fukutin gene. The main features of FCMD are a combination of infantile-onset hypotonia, generalized muscle weakness, eye abnormalities, and mental retardation associated with cortical migration defects, and most patients are never able to walk. To date, the development of a quantitative motor scale for FMCD has been difficult due to the moderate-to-severe intellectual impairment that accompanies FCMD. Gross motor function measure (GMFM), originally developed as a quantitative motor scale for cerebral palsy, can precisely and quantitatively assess motor function without complicated instructions, and was recently reported to be useful in the assessment of Down syndrome and spinal muscular atrophy. To confirm the validity of GMFM for the assessment of FCMD, 41 FCMD patients (age range: 0.6-24.4 years) were recruited for this study. The GMFM scores correlated significantly with those of two previously used motor scales, and the time-dependent change in GMFM scores was consistent with the natural course of FCMD. The inter-rater reliability, based on determinations made by four physiotherapists blinded to each other's assessment results, was excellent. We concluded GMFM to be a useful and valid measure of motor function in FCMD patients.

  5. Controlling the specificity of modularly assembled small molecules for RNA via ligand module spacing: targeting the RNAs that cause myotonic muscular dystrophy.

    PubMed

    Lee, Melissa M; Childs-Disney, Jessica L; Pushechnikov, Alexei; French, Jonathan M; Sobczak, Krzysztof; Thornton, Charles A; Disney, Matthew D

    2009-12-02

    Myotonic muscular dystrophy types 1 and 2 (DM1 and DM2, respectively) are caused by expansions of repeating nucleotides in noncoding regions of RNA. In DM1, the expansion is an rCUG triplet repeat, whereas the DM2 expansion is an rCCUG quadruplet repeat. Both RNAs fold into hairpin structures with periodically repeating internal loops separated by two 5'GC/3'CG base pairs. The sizes of the loops, however, are different: the DM1 repeat forms 1 x 1 nucleotide UU loops while the DM2 repeat forms 2 x 2 nucleotide 5'CU/3'UC loops. DM is caused when the expanded repeats bind the RNA splicing regulator Muscleblind-like 1 protein (MBNL1), thus compromising its function. Therefore, one potential therapeutic strategy for these diseases is to prevent MBNL1 from binding the toxic RNA repeats. Previously, we designed nanomolar inhibitors of the DM2-MBNL1 interaction by modularly assembling 6'-N-5-hexyonate kanamycin A (K) onto a peptoid backbone. The K ligand binds the 2 x 2 pyrimidine-rich internal loops found in the DM2 RNA with high affinity. The best compound identified from that study contains three K modules separated by four propylamine spacing modules and is 20-fold selective for the DM2 RNA over the DM1 RNA. Because the modularly assembled K-containing compounds also bound the DM1 RNA, albeit with lower affinity, and because the loop size is different, we hypothesized that the optimal DM1 RNA binder may display K modules separated by a shorter distance. Indeed, here the ideal DM1 RNA binder has only two propylamine spacing modules separating the K ligands. Peptoids displaying three and four K modules on a peptoid scaffold bind the DM1 RNA with K(d)'s of 20 nM (3-fold selective for DM1 over DM2) and 4 nM (6-fold selective) and inhibit the RNA-protein interaction with IC(50)'s of 40 and 7 nM, respectively. Importantly, by coupling the two studies together, we have determined that appropriate spacing can affect binding selectivity by 60-fold (20- x 3-fold). The trimer and

  6. Model organisms in the fight against muscular dystrophy: lessons from drosophila and Zebrafish.

    PubMed

    Plantié, Emilie; Migocka-Patrzałek, Marta; Daczewska, Małgorzata; Jagla, Krzysztof

    2015-04-09

    Muscular dystrophies (MD) are a heterogeneous group of genetic disorders that cause muscle weakness, abnormal contractions and muscle wasting, often leading to premature death. More than 30 types of MD have been described so far; those most thoroughly studied are Duchenne muscular dystrophy (DMD), myotonic dystrophy type 1 (DM1) and congenital MDs. Structurally, physiologically and biochemically, MDs affect different types of muscles and cause individual symptoms such that genetic and molecular pathways underlying their pathogenesis thus remain poorly understood. To improve our knowledge of how MD-caused muscle defects arise and to find efficacious therapeutic treatments, different animal models have been generated and applied. Among these, simple non-mammalian Drosophila and zebrafish models have proved most useful. This review discusses how zebrafish and Drosophila MD have helped to identify genetic determinants of MDs and design innovative therapeutic strategies with a special focus on DMD, DM1 and congenital MDs.

  7. Leber congenital amaurosis/early-onset severe retinal dystrophy: clinical features, molecular genetics and therapeutic interventions.

    PubMed

    Kumaran, Neruban; Moore, Anthony T; Weleber, Richard G; Michaelides, Michel

    2017-09-01

    Leber congenital amaurosis (LCA) and early-onset severe retinal dystrophy (EOSRD) are both genetically and phenotypically heterogeneous, and characterised clinically by severe congenital/early infancy visual loss, nystagmus, amaurotic pupils and markedly reduced/absent full-field electroretinograms. The vast genetic heterogeneity of inherited retinal disease has been established over the last 10 - 20 years, with disease-causing variants identified in 25 genes to date associated with LCA/EOSRD, accounting for 70-80% of cases, with thereby more genes yet to be identified. There is now far greater understanding of the structural and functional associations seen in the various LCA/EOSRD genotypes. Subsequent development/characterisation of LCA/EOSRD animal models has shed light on the underlying pathogenesis and allowed the demonstration of successful rescue with gene replacement therapy and pharmacological intervention in multiple models. These advancements have culminated in more than 12 completed, ongoing and anticipated phase I/II and phase III gene therapy and pharmacological human clinical trials. This review describes the clinical and genetic characteristics of LCA/EOSRD and the differential diagnoses to be considered. We discuss in further detail the diagnostic clinical features, pathophysiology, animal models and human treatment studies and trials, in the more common genetic subtypes and/or those closest to intervention. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Bcl-2 Inhibits the Innate Immune Response during Early Pathogenesis of Murine Congenital Muscular Dystrophy

    PubMed Central

    Jeudy, Sheila; Wardrop, Katherine E.; Alessi, Amy; Dominov, Janice A.

    2011-01-01

    Laminin α2 (LAMA2)-deficient congenital muscular dystrophy is a severe, early-onset disease caused by abnormal levels of laminin 211 in the basal lamina leading to muscle weakness, transient inflammation, muscle degeneration and impaired mobility. In a Lama2-deficient mouse model for this disease, animal survival is improved by muscle-specific expression of the apoptosis inhibitor Bcl-2, conferred by a MyoD-hBcl-2 transgene. Here we investigated early disease stages in this model to determine initial pathological events and effects of Bcl-2 on their progression. Using quantitative immunohistological and mRNA analyses we show that inflammation occurs very early in Lama2-deficient muscle, some aspects of which are reduced or delayed by the MyoD-hBcl-2 transgene. mRNAs for innate immune response regulators, including multiple Toll-like receptors (TLRs) and the inflammasome component NLRP3, are elevated in diseased muscle compared with age-matched controls expressing Lama2. MyoD-hBcl-2 inhibits induction of TLR4, TLR6, TLR7, TLR8 and TLR9 in Lama2-deficient muscle compared with non-transgenic controls, and leads to reduced infiltration of eosinophils, which are key death effector cells. This congenital disease model provides a new paradigm for investigating cell death mechanisms during early stages of pathogenesis, demonstrating that interactions exist between Bcl-2, a multifunctional regulator of cell survival, and the innate immune response. PMID:21850221

  9. Leber congenital amaurosis/early-onset severe retinal dystrophy: clinical features, molecular genetics and therapeutic interventions

    PubMed Central

    Kumaran, Neruban; Moore, Anthony T; Weleber, Richard G; Michaelides, Michel

    2017-01-01

    Leber congenital amaurosis (LCA) and early-onset severe retinal dystrophy (EOSRD) are both genetically and phenotypically heterogeneous, and characterised clinically by severe congenital/early infancy visual loss, nystagmus, amaurotic pupils and markedly reduced/absent full-field electroretinograms. The vast genetic heterogeneity of inherited retinal disease has been established over the last 10 - 20 years, with disease-causing variants identified in 25 genes to date associated with LCA/EOSRD, accounting for 70–80% of cases, with thereby more genes yet to be identified. There is now far greater understanding of the structural and functional associations seen in the various LCA/EOSRD genotypes. Subsequent development/characterisation of LCA/EOSRD animal models has shed light on the underlying pathogenesis and allowed the demonstration of successful rescue with gene replacement therapy and pharmacological intervention in multiple models. These advancements have culminated in more than 12 completed, ongoing and anticipated phase I/II and phase III gene therapy and pharmacological human clinical trials. This review describes the clinical and genetic characteristics of LCA/EOSRD and the differential diagnoses to be considered. We discuss in further detail the diagnostic clinical features, pathophysiology, animal models and human treatment studies and trials, in the more common genetic subtypes and/or those closest to intervention. PMID:28689169

  10. Prospect of gene therapy for cardiomyopathy in hereditary muscular dystrophy

    PubMed Central

    Yue, Yongping; Binalsheikh, Ibrahim M.; Leach, Stacey B.; Domeier, Timothy L.; Duan, Dongsheng

    2016-01-01

    Introduction Cardiac involvement is a common feature in muscular dystrophies. It presents as heart failure and/or arrhythmia. Traditionally, dystrophic cardiomyopathy is treated with symptom-relieving medications. Identification of disease-causing genes and investigation on pathogenic mechanisms have opened new opportunities to treat dystrophic cardiomyopathy with gene therapy. Replacing/repairing the mutated gene and/or targeting the pathogenic process/mechanisms using alternative genes may attenuate heart disease in muscular dystrophies. Areas covered Duchenne muscular dystrophy is the most common muscular dystrophy. Duchenne cardiomyopathy has been the primary focus of ongoing dystrophic cardiomyopathy gene therapy studies. Here, we use Duchenne cardiomyopathy gene therapy to showcase recent developments and to outline the path forward. We also discuss gene therapy status for cardiomyopathy associated with limb-girdle and congenital muscular dystrophies, and myotonic dystrophy. Expert opinion Gene therapy for dystrophic cardiomyopathy has taken a slow but steady path forward. Preclinical studies over the last decades have addressed many fundamental questions. Adeno-associated virus-mediated gene therapy has significantly improved the outcomes in rodent models of Duchenne and limb girdle muscular dystrophies. Validation of these encouraging results in large animal models will pave the way to future human trials. PMID:27340611

  11. Cognitive behaviour therapy plus aerobic exercise training to increase activity in patients with myotonic dystrophy type 1 (DM1) compared to usual care (OPTIMISTIC): study protocol for randomised controlled trial.

    PubMed

    van Engelen, Baziel

    2015-05-23

    Myotonic dystrophy type 1 (DM1) is a rare, inherited chronic progressive disease as well as an autosomal dominant multi-systemic disorder. It is probably one of the most common adult forms of muscular dystrophy, with a prevalence of approximately 10 per 100,000 people affected. With 733 million people in Europe, we estimate that 75,000 people in Europe are affected with DM1. OPTIMISTIC is a multi-centre, randomised trial designed to compare an intervention comprising cognitive behavioural therapy (CBT) plus graded exercise therapy against standard care. Participants will be recruited from myotonic dystrophy clinics and neuromuscular centres in France, Germany, the Netherlands and the United Kingdom. A sample size of 208 individuals is needed. To allow for some potential loss to follow-up, a total of 296 male and female patients aged 18 years and older with genetically proven classical or adult DM1 and suffering from severe fatigue (only DM1 patients with a Checklist Individual Strength (CIS) subscale fatigue severity score ≥ 35 are likely to benefit from the intervention), able to walk independently and able to complete the trial interventions will be included. The primary outcome of the study is the score on the DM1-Activ scale, which is a measure of activity and participation for patients with DM1. Secondary outcomes include the 6-minute walk test, objective physical activity measured with an accelerometer, quality of life and cognitive measures. The trial will also collect data on potential effect modifiers of the short- and long-term clinical response, including pain, muscular impairment and cognitive-behavioural variables. In addition, OPTIMISTIC will identify genetic factors that predict outcome and potential biomarkers as surrogate outcome measures that best explain the observed clinical variation. OPTIMISTIC will not only provide effectiveness data on an intervention that could fill a treatment-gap for DM1 patients but will also improve our understanding

  12. Breaches of the pial basement membrane are associated with defective dentate gyrus development in mouse models of congenital muscular dystrophies.

    PubMed

    Li, Jing; Yu, Miao; Feng, Gang; Hu, Huaiyu; Li, Xiaofeng

    2011-11-07

    A subset of congenital muscular dystrophies (CMDs) has central nervous system manifestations. There are good mouse models for these CMDs that include POMGnT1 knockout, POMT2 knockout and Large(myd) mice with all exhibiting defects in dentate gyrus. It is not known how the abnormal dentate gyrus is formed during the development. In this study, we conducted a detailed morphological examination of the dentate gyrus in adult and newborn POMGnT1 knockout, POMT2 knockout, and Large(myd) mice by immunofluorescence staining and electron microscopic analyses. We observed that the pial basement membrane overlying the dentate gyrus was disrupted and there was ectopia of granule cell precursors through the breached pial basement membrane. Besides these, the knockout dentate gyrus exhibited reactive gliosis in these mouse models. Thus, breaches in the pial basement membrane are associated with defective dentate gyrus development in mouse models of congenital muscular dystrophies.

  13. Genetics Home Reference: myotonic dystrophy

    MedlinePlus

    ... mutated gene produces an expanded version of messenger RNA , which is a molecular blueprint of the gene ... the production of proteins. The abnormally long messenger RNA forms clumps inside the cell that interfere with ...

  14. B3GALNT2 is a gene associated with congenital muscular dystrophy with brain malformations.

    PubMed

    Hedberg, Carola; Oldfors, Anders; Darin, Niklas

    2014-05-01

    Congenital muscular dystrophies associated with brain malformations are a group of disorders frequently associated with aberrant glycosylation of α-dystroglycan. They include disease entities such a Walker-Warburg syndrome, muscle-eye-brain disease and various other clinical phenotypes. Different genes involved in glycosylation of α-dystroglycan are associated with these dystroglycanopathies. We describe a 5-year-old girl with psychomotor retardation, ataxia, spasticity, muscle weakness and increased serum creatine kinase levels. Immunhistochemistry of skeletal muscle revealed reduced glycosylated α-dystroglycan. Magnetic resonance imaging of the brain at 3.5 years of age showed increased T2 signal from supratentorial and infratentorial white matter, a hypoplastic pons and subcortical cerebellar cysts. By whole exome sequencing, the patient was identified to be compound heterozygous for a one-base duplication and a missense mutation in the gene B3GALNT2 (β-1,3-N-acetylgalactosaminyltransferase 2; B3GalNAc-T2). This patient showed a milder phenotype than previously described patients with mutations in the B3GALNT2 gene.

  15. Role of Decorin Core Protein in Collagen Organisation in Congenital Stromal Corneal Dystrophy (CSCD)

    PubMed Central

    Kamma-Lorger, Christina S.; Pinali, Christian; Martínez, Juan Carlos; Harris, Jon; Young, Robert D.; Bredrup, Cecilie; Crosas, Eva; Malfois, Marc; Rødahl, Eyvind

    2016-01-01

    The role of Decorin in organising the extracellular matrix was examined in normal human corneas and in corneas from patients with Congenital Stromal Corneal Dystrophy (CSCD). In CSCD, corneal clouding occurs due to a truncating mutation (c.967delT) in the decorin (DCN) gene. Normal human Decorin protein and the truncated one were reconstructed in silico using homology modelling techniques to explore structural changes in the diseased protein. Corneal CSCD specimens were also examined using 3-D electron tomography and Small Angle X-ray diffraction (SAXS), to image the collagen-proteoglycan arrangement and to quantify fibrillar diameters, respectively. Homology modelling showed that truncated Decorin had a different spatial geometry to the normal one, with the truncation removing a major part of the site that interacts with collagen, compromising its ability to bind effectively. Electron tomography showed regions of abnormal stroma, where collagen fibrils came together to form thicker fibrillar structures, showing that Decorin plays a key role in the maintenance of the order in the normal corneal extracellular matrix. Average diameter of individual fibrils throughout the thickness of the cornea however remained normal. PMID:26828927

  16. The value of respiratory muscle testing in a child with congenital muscular dystrophy

    PubMed Central

    Khirani, Sonia; Dabaj, Ivana; Amaddeo, Alessandro; Ramirez, Adriana; Quijano-Roy, Susana; Fauroux, Brigitte

    2014-01-01

    Respiratory muscle testing is often limited to noninvasive volitional tests such as vital capacity and maximal static pressures. We report the case of a 12-year-old boy with congenital muscular dystrophy (CMD) in whom invasive and non-volitional respiratory muscle tests showed an elective diaphragmatic dysfunction with the preservation of expiratory muscle strength. This finding, coupled with a clinical phenotype associating diffuse muscle atrophy with finger hyperlaxity and proximal contractures, strengthened the suspicion of Ullrich CMD. Skin-cultured fibroblasts showed intracellular retention of collagen 6 (COL6), muscle magnetic resonance imaging was typical of COL6 myopathy, and molecular studies identified a COL6 gene mutation (COL6A2 c.954+2T>C). The diagnosis of a diaphragmatic dysfunction led to a sleep study that evidenced periods of hypoxemia which justified nocturnal noninvasive ventilation. This case report highlights the benefit of assessing respiratory muscles, through invasive procedure, to assist in clinical diagnosis and to guide clinical management. PMID:25473580

  17. Laminin-111 improves muscle repair in a mouse model of merosin-deficient congenital muscular dystrophy

    PubMed Central

    Van Ry, Pam M.; Minogue, Priscilla; Hodges, Bradley L.; Burkin, Dean J.

    2014-01-01

    Merosin-deficient congenital muscular dystrophy type 1A (MDC1A) is a severe and fatal muscle-wasting disease with no cure. MDC1A patients and the dyW−/− mouse model exhibit severe muscle weakness, demyelinating neuropathy, failed muscle regeneration and premature death. We have recently shown that laminin-111, a form of laminin found in embryonic skeletal muscle, can substitute for the loss of laminin-211/221 and prevent muscle disease progression in the dyW−/− mouse model. What is unclear from these studies is whether laminin-111 can restore failed regeneration to laminin-α2-deficient muscle. To investigate the potential of laminin-111 protein therapy to improve muscle regeneration, laminin-111 or phosphate-buffered saline-treated laminin-α2-deficient muscle was damaged with cardiotoxin and muscle regeneration quantified. Our results show laminin-111 treatment promoted an increase in myofiber size and number, and an increased expression of α7β1 integrin, Pax7, myogenin and embryonic myosin heavy chain, indicating a restoration of the muscle regenerative program. Together, our results show laminin-111 restores muscle regeneration to laminin-α2-deficient muscle and further supports laminin-111 protein as a therapy for the treatment of MDC1A. PMID:24009313

  18. Laminin-α2 Chain-Deficient Congenital Muscular Dystrophy: Pathophysiology and Development of Treatment.

    PubMed

    Durbeej, Madeleine

    2015-01-01

    Laminin-211 is a major constituent of the skeletal muscle basement membrane. It stabilizes skeletal muscle and influences signal transduction events from the myomatrix to the muscle cell. Mutations in the gene encoding the α2 chain of laminin-211 lead to congenital muscular dystrophy type 1A (MDC1A), a life-threatening disease characterized by severe hypotonia, progressive muscle weakness, and joint contractures. Common complications include severely impaired motor ability, respiratory failure, and feeding difficulties. Several adequate animal models for laminin-α2 chain deficiency exist and analyses of different MDC1A mouse models have led to a significant improvement in our understanding of MDC1A pathogenesis. Importantly, the animal models have been indispensable tools for the preclinical development of new therapeutic approaches for laminin-α2 chain deficiency, highlighting a number of important disease driving mechanisms that can be targeted by pharmacological approaches. In this chapter, I will describe laminin-211 and discuss the cellular and molecular pathophysiology of MDC1A as well as progression toward development of treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Ullrich congenital muscular dystrophy: clinicopathological features, natural history and pathomechanism(s).

    PubMed

    Yonekawa, Takahiro; Nishino, Ichizo

    2015-03-01

    Collagen VI is widely distributed throughout extracellular matrices (ECMs) in various tissues. In skeletal muscle, collagen VI is particularly concentrated in and adjacent to basement membranes of myofibers. Ullrich congenital muscular dystrophy (UCMD) is caused by mutations in either COL6A1, COL6A2 or COL6A3 gene, thereby leading to collagen VI deficiency in the ECM. It is known to occur through either recessive or dominant genetic mechanism, the latter most typically by de novo mutations. UCMD is well defined by the clinicopathological hallmarks including distal hyperlaxity, proximal joint contractures, protruding calcanei, scoliosis and respiratory insufficiency. Recent reports have depicted the robust natural history of UCMD; that is, loss of ambulation by early teenage years, rapid decline in respiratory function by 10 years of age and early-onset, rapidly progressive scoliosis. Muscle pathology is characterised by prominent interstitial fibrosis disproportionate to the relative paucity of necrotic and regenerating fibres. To date, treatment for patients is supportive for symptoms such as joint contractures, respiratory failure and scoliosis. There have been clinical trials based on the theory of mitochondrion-mediated myofiber apoptosis or impaired autophagy. Furthermore, the fact that collagen VI producing cells in skeletal muscle are interstitial mesenchymal cells can support proof of concept for stem cell-based therapy.

  20. Bioenergetic Impairment in Congenital Muscular Dystrophy Type 1A and Leigh Syndrome Muscle Cells

    PubMed Central

    Fontes-Oliveira, Cibely C.; Steinz, Maarten; Schneiderat, Peter; Mulder, Hindrik; Durbeej, Madeleine

    2017-01-01

    Skeletal muscle has high energy requirement and alterations in metabolism are associated with pathological conditions causing muscle wasting and impaired regeneration. Congenital muscular dystrophy type 1A (MDC1A) is a severe muscle disorder caused by mutations in the LAMA2 gene. Leigh syndrome (LS) is a neurometabolic disease caused by mutations in genes related to mitochondrial function. Skeletal muscle is severely affected in both diseases and a common feature is muscle weakness that leads to hypotonia and respiratory problems. Here, we have investigated the bioenergetic profile in myogenic cells from MDC1A and LS patients. We found dysregulated expression of genes related to energy production, apoptosis and proteasome in myoblasts and myotubes. Moreover, impaired mitochondrial function and a compensatory upregulation of glycolysis were observed when monitored in real-time. Also, alterations in cell cycle populations in myoblasts and enhanced caspase-3 activity in myotubes were observed. Thus, we have for the first time demonstrated an impairment of the bioenergetic status in human MDC1A and LS muscle cells, which could contribute to cell cycle disturbance and increased apoptosis. Our findings suggest that skeletal muscle metabolism might be a promising pharmacological target in order to improve muscle function, energy efficiency and tissue maintenance of MDC1A and LS patients. PMID:28367954

  1. Behavioral Responses in Animal Model of Congenital Muscular Dystrophy 1D.

    PubMed

    Comim, Clarissa M; Schactae, Aryadnne L; Soares, Jaime A; Ventura, Letícia; Freiberger, Viviane; Mina, Francielle; Dominguini, Diogo; Vainzof, Mariz; Quevedo, João

    2016-01-01

    Congenital muscular dystrophies 1D (CMD1D) present a mutation on the LARGE gene and are characterized by an abnormal glycosylation of α-dystroglycan (α-DG), strongly implicated as having a causative role in the development of central nervous system abnormalities such as cognitive impairment seen in patients. However, in the animal model of CMD1D, the brain involvement remains unclear. Therefore, the objective of this study is to evaluate the cognitive involvement in the Large(myd) mice. To this aim, we used adult homozygous, heterozygous, and wild-type mice. The mice underwent six behavioral tasks: habituation to an open field, step-down inhibitory avoidance, continuous multiple trials step-down inhibitory avoidance task, object recognition, elevated plus-maze, and forced swimming test. It was observed that Large(myd) individuals presented deficits on the habituation to the open field, step down inhibitory avoidance, continuous multiple-trials step-down inhibitory avoidance, object recognition, and forced swimming. This study shows the first evidence that abnormal glycosylation of α-DG may be affecting memory storage and restoring process in an animal model of CMD1D.

  2. Cyclosporine A treatment for Ullrich congenital muscular dystrophy: a cellular study of mitochondrial dysfunction and its rescue.

    PubMed

    Hicks, D; Lampe, A K; Laval, S H; Allamand, V; Jimenez-Mallebrera, C; Walter, M C; Muntoni, F; Quijano-Roy, S; Richard, P; Straub, V; Lochmüller, H; Bushby, K M D

    2009-01-01

    Mutations in COL6A1, COL6A2 and COL6A3, the genes which encode the extra-cellular matrix component collagen VI, lead to Bethlem myopathy and Ullrich congenital muscular dystrophy (UCMD). Although the Col6a1(-/-) null mouse has an extremely mild neuromuscular phenotype, a mitochondrial defect has been demonstrated, linked to dysregulation of the mitochondrial permeability transition pore (PTP) opening. This finding has been replicated in UCMD muscle cells in culture, providing justification for a clinical trial using cyclosporine A, an inhibitor of PTP opening. We investigated whether PTP dysregulation could be detected in UCMD fibroblasts (the predominant source of muscle collagen VI), in myoblast cells from patients with other diseases and its response to rescue agents other than collagen VI. Although we confirm the presence of PTP dysregulation in muscle-derived cultures from two UCMD patients, fibroblasts from the same patients and the majority of fibroblasts from other well-characterized UCMD patients behave normally. PTP dysregulation is found in limb girdle muscular dystrophy (LGMD) type 2B myoblasts but not in myoblasts from patients with Bethlem myopathy, merosin-deficient congenital muscular dystrophy, LGMD2A, Duchenne muscular dystrophy and Leigh syndrome. In addition to rescue by cyclosporine A and collagen VI, this cellular phenotype was also rescued by other extra-cellular matrix constituents (laminin and collagen I). As the muscle derived cultures demonstrating PTP dysregulation shared poor growth in culture and lack of desmin labelling, we believe that PTP dysregulation may be a particular characteristic of the state of these cells in culture and is not specific to the collagen VI defect, and can in any case be rescued by a range of extra-cellular matrix components. Further work is needed on the relationship of PTP dysregulation with UCMD pathology.

  3. Dysregulation of calcium homeostasis in muscular dystrophies.

    PubMed

    Vallejo-Illarramendi, Ainara; Toral-Ojeda, Ivan; Aldanondo, Garazi; López de Munain, Adolfo

    2014-10-08

    Muscular dystrophies are a group of diseases characterised by the primary wasting of skeletal muscle, which compromises patient mobility and in the most severe cases originate a complete paralysis and premature death. Existing evidence implicates calcium dysregulation as an underlying crucial event in the pathophysiology of several muscular dystrophies, such as dystrophinopathies, calpainopathies or myotonic dystrophy among others. Duchenne muscular dystrophy is the most frequent myopathy in childhood, and calpainopathy or LGMD2A is the most common form of limb-girdle muscular dystrophy, whereas myotonic dystrophy is the most frequent inherited muscle disease worldwide. In this review, we summarise recent advances in our understanding of calcium ion cycling through the sarcolemma, the sarcoplasmic reticulum and mitochondria, and its involvement in the pathogenesis of these dystrophies. We also discuss some of the clinical implications of recent findings regarding Ca2+ handling as well as novel approaches to treat muscular dystrophies targeting Ca2+ regulatory proteins.

  4. Nutritional Status Evaluation in Patients Affected by Bethlem Myopathy and Ullrich Congenital Muscular Dystrophy

    PubMed Central

    Toni, Silvia; Morandi, Riccardo; Busacchi, Marcello; Tardini, Lucia; Merlini, Luciano; Battistini, Nino Carlo; Pellegrini, Massimo

    2014-01-01

    Collagen VI mutations lead to disabling myopathies like Bethlem myopathy (BM) and Ullrich congenital muscular dystrophy (UCMD). We have investigated the nutritional and metabolic status of one UCMD and seven BM patients (five female, three male, mean age 31 ± 9 years) in order to find a potential metabolic target for nutritional intervention. For this study, we used standard anthropometric tools, such as BMI evaluation and body circumference measurements. All results were compared to dual-energy X-ray absorptiometry (DXA), considered the “gold standard” method. Energy intake of each patient was evaluated through longitudinal methods (7-day food diary) while resting energy expenditure (REE) was predicted using specific equations and measured by indirect calorimetry. Clinical evaluation included general and nutritional blood and urine laboratory analyses and quantitative muscle strength measurement by hand-held dynamometry. BM and UCMD patients showed an altered body composition, characterized by low free fat mass (FFM) and high fat mass (FM), allowing us to classify them as sarcopenic, and all but one as sarcopenic-obese. Another main result was the negative correlation between REE/FFM ratio (basal energy expenditure per kilograms of fat-free mass) and the severity of the disease, as defined by the muscle megascore (correlation coefficient −0.955, P-value <0.001). We postulate that the increase of the REE/FFM ratio in relation to the severity of the disease may be due to an altered and pathophysiological loss of energetic efficiency at the expense of skeletal muscle. We show that a specific metabolic disequilibrium is related to the severity of the disease, which may represent a target for a nutritional intervention in these patients. PMID:25477818

  5. Triggering regeneration and tackling apoptosis: a combinatorial approach to treating congenital muscular dystrophy type 1 A.

    PubMed

    Yamauchi, Jenny; Kumar, Ajay; Duarte, Lina; Mehuron, Thomas; Girgenrath, Mahasweta

    2013-11-01

    Merosin-deficient congenital muscular dystrophy type 1A (MDC1A) is an autosomal recessive disorder caused by mutations in the laminin-α2 gene (OMIM: 607855). Currently, no treatment other than palliative care exists for this disease. In our previous work, genetic interventions in the Lama2(Dy-w) mouse model for MDC1A demonstrated that limited regeneration and uncontrolled apoptosis are important drivers of this disease. However, targeting one of these disease drivers without addressing the other results in only partial rescue of the phenotype. The present study was designed to determine whether utilizing a combinatorial treatment approach can lead to a more profound amelioration of the disease pathology. To accomplish this task, we generated Bax-null Lama2(Dy-w)mice that overexpressed muscle-specific IGF-1 (Lama2(Dy-w)Bax(-/-)+IGF-1tg). Further to test the translational potential of IGF-1 administration in combination with Bax inhibition, we treated Lama2(Dy-w)Bax(-/-) mice postnatally with systemic recombinant human IGF-1 (IPLEX™). These two combinatorial treatments lead to similar, promising outcomes. In addition to increased body and muscle weights, both transgenic overexpression and systemic administration of IGF-1 combined with Bax-inhibition resulted in improved muscle phenotype and locomotory function that were nearly indistinguishable from wild-type mice. These results provide a fundamental proof of concept that justifies the use of a combination therapy as an effective treatment for MDC1A and highlights a compelling argument toward shifting the paradigm in treating multifaceted neuromuscular diseases.

  6. Reviewing Large LAMA2 Deletions and Duplications in Congenital Muscular Dystrophy Patients.

    PubMed

    Oliveira, Jorge; Gonçalves, Ana; Oliveira, Márcia E; Fineza, Isabel; Pavanello, Rita C M; Vainzof, Mariz; Bronze-da-Rocha, Elsa; Santos, Rosário; Sousa, Mário

    2014-01-01

    Congenital muscular dystrophy (CMD) type 1A (MDC1A) is caused by recessive mutations in laminin-α2 (LAMA2) gene. Laminin-211, a heterotrimeric glycoprotein that contains the α2 chain, is crucial for muscle stability establishing a bond between the sarcolemma and the extracellular matrix. More than 215 mutations are listed in the locus specific database (LSDB) for LAMA2 gene (May 2014). A limited number of large deletions/duplications have been reported in LAMA2. Our main objective was the identification of additional large rearrangements in LAMA2 found in CMD patients and a systematic review of cases in the literature and LSDB. In four of the fifty-two patients studied over the last 10 years, only one heterozygous mutation was identified, after sequencing and screening for a frequent LAMA2 deletion. Initial screening of large mutations was performed by multiplex ligation-dependent probe application (MLPA). Further characterization implied several techniques: long-range PCR, cDNA and Southern-blot analysis. Three novel large deletions in LAMA2 and the first pathogenic large duplication were successfully identified, allowing a definitive molecular diagnosis, carrier screening and prenatal diagnosis. A total of fifteen deletions and two duplications previously reported were also reviewed. Two possible mutational "hotspots" for deletions may exist, the first encompassing exons 3 and 4 and second in the 3' region (exons 56 to 65) of LAMA2. Our findings show that this type of mutation is fairly frequent (18.4% of mutated alleles) and is underestimated in the literature. It is important to include the screening of large deletions/duplications as part of the genetic diagnosis strategy.

  7. Refined mapping of a gene responsible for Fukuyama-type congenital muscular dystrophy: Evidence for strong linkage disequilibrium

    SciTech Connect

    Toda, Tatsushi; Ikegawa, Shiro; Okui, Keiko; Nakamura, Yusuke; Kanazawa, Ichiro; Kondo, Eri; Saito, Kayoko; Fukuyama, Yukio; Yoshioka, Mieko; Kumagai, Toshiyuki

    1994-11-01

    Fukuyama-type congenital muscular dystrophy (FCMD), the second most common form of childhood muscular dystrophy in Japan, is an autosomal recessive severe muscular dystrophy associated with an anomaly of the brain. After our initial mapping of the FCMD locus to chromosome 9q31-33, we further defined the locus within a region of {approximately}5 cM between loci D9S127 and CA246, by homozygosity mapping in patients born to consanguineous marriages and by recombination analyses in other families. We also found evidence for strong linkage disequilibrium between FCMD and a polymorphic microsatellite marker, mfd220, which showed no recombination and a lod score of (Z) 17.49. A {open_quotes}111-bp{close_quotes} allele for the mfd220 was observed in 22 (34%) of 64 FCMD chromosomes, but it was present in only 1 of 120 normal chromosomes. This allelic association with FCMD was highly significant ({chi}{sup 2} = 50.7; P < .0001). Hence, we suspect that the FCMD gene could lie within a few hundred kilobases of the mfd220 locus. 32 refs., 2 figs., 2 tabs.

  8. Proximal myopathy with focal depletion of mitochondria and megaconial congenital muscular dystrophy are allelic conditions caused by mutations in CHKB.

    PubMed

    Brady, L; Giri, M; Provias, J; Hoffman, E; Tarnopolsky, M

    2016-02-01

    We recently evaluated two of the original three patients (siblings) diagnosed with Proximal Myopathy with Focal Depletion of Mitochondria. The condition was named for the distinctive pattern of enlarged mitochondria around the periphery of muscle fibres with a complete absence in the middle. These siblings, aged 37 and 40, are cognitively normal with mild non-progressive muscle weakness and a susceptibility to rhabdomyolysis. Both were shown to be compound heterozygotes for novel mutations (c.263C>T + c.950T>A) in CHKB, the gene currently associated with Megaconial Congenital Muscular Dystrophy. Individuals with this condition have early-onset muscle weakness and profound intellectual disability but share the same unique pattern on muscle biopsy as was noted in Proximal Myopathy with Focal Depletion of Mitochondria; focal depletion of mitochondria was surrounded by abnormally large "megaconial" mitochondria. Thus the phenotypic spectrum of CHKB mutations ranges from a congenital muscular dystrophy with intellectual disability to a later-onset non-progressive muscular weakness with normal cognition.

  9. A polymorphism in the MSH3 mismatch repair gene is associated with the levels of somatic instability of the expanded CTG repeat in the blood DNA of myotonic dystrophy type 1 patients.

    PubMed

    Morales, Fernando; Vásquez, Melissa; Santamaría, Carolina; Cuenca, Patricia; Corrales, Eyleen; Monckton, Darren G

    2016-04-01

    Somatic mosaicism of the expanded CTG repeat in myotonic dystrophy type 1 is age-dependent, tissue-specific and expansion-biased, contributing toward the tissue-specificity and progressive nature of the symptoms. Previously, using regression modelling of repeat instability we showed that variation in the rate of somatic expansion in blood DNA contributes toward variation in age of onset, directly implicating somatic expansion in the disease pathway. Here, we confirm these results using a larger more genetically homogenous Costa Rican DM1 cohort (p<0.001). Interestingly, we also provide evidence that supports subtle sex-dependent differences in repeat length-dependent age at onset and somatic mutational dynamics. Previously, we demonstrated that variation in the rate of somatic expansion was a heritable quantitative trait. Given the important role that DNA mismatch repair genes play in mediating expansions in mouse models, we tested for modifier gene effects with 13 DNA mismatch gene polymorphisms (one each in MSH2, PMS2, MSH6 and MLH1; and nine in MSH3). After correcting for allele length and age effects, we identified three polymorphisms in MSH3 that were associated with variation in somatic instability: Rs26279 (p=0.003); Rs1677658 (p=0.009); and Rs10168 (p=0.031). However, only the association with Rs26279 remained significant after multiple testing correction. Although we revealed a statistically significant association between Rs26279 and somatic instability, we did not detect an association with the age at onset. Individuals with the A/A genotype for Rs26279 tended to show a greater propensity to expand the CTG repeat than other genotypes. Interestingly, this SNP results in an amino acid change in the critical ATPase domain of MSH3 and is potentially functionally dimorphic. These data suggest that MSH3 is a key player in generating somatic variation in DM1 patients and further highlight MSH3 as a potential therapeutic target.

  10. Mutations in GDP-Mannose Pyrophosphorylase B Cause Congenital and Limb-Girdle Muscular Dystrophies Associated with Hypoglycosylation of α-Dystroglycan

    PubMed Central

    Carss, Keren J.; Stevens, Elizabeth; Foley, A. Reghan; Cirak, Sebahattin; Riemersma, Moniek; Torelli, Silvia; Hoischen, Alexander; Willer, Tobias; van Scherpenzeel, Monique; Moore, Steven A.; Messina, Sonia; Bertini, Enrico; Bönnemann, Carsten G.; Abdenur, Jose E.; Grosmann, Carla M.; Kesari, Akanchha; Punetha, Jaya; Quinlivan, Ros; Waddell, Leigh B.; Young, Helen K.; Wraige, Elizabeth; Yau, Shu; Brodd, Lina; Feng, Lucy; Sewry, Caroline; MacArthur, Daniel G.; North, Kathryn N.; Hoffman, Eric; Stemple, Derek L.; Hurles, Matthew E.; van Bokhoven, Hans; Campbell, Kevin P.; Lefeber, Dirk J.; Lin, Yung-Yao; Muntoni, Francesco

    2013-01-01

    Congenital muscular dystrophies with hypoglycosylation of α-dystroglycan (α-DG) are a heterogeneous group of disorders often associated with brain and eye defects in addition to muscular dystrophy. Causative variants in 14 genes thought to be involved in the glycosylation of α-DG have been identified thus far. Allelic mutations in these genes might also cause milder limb-girdle muscular dystrophy phenotypes. Using a combination of exome and Sanger sequencing in eight unrelated individuals, we present evidence that mutations in guanosine diphosphate mannose (GDP-mannose) pyrophosphorylase B (GMPPB) can result in muscular dystrophy variants with hypoglycosylated α-DG. GMPPB catalyzes the formation of GDP-mannose from GTP and mannose-1-phosphate. GDP-mannose is required for O-mannosylation of proteins, including α-DG, and it is the substrate of cytosolic mannosyltransferases. We found reduced α-DG glycosylation in the muscle biopsies of affected individuals and in available fibroblasts. Overexpression of wild-type GMPPB in fibroblasts from an affected individual partially restored glycosylation of α-DG. Whereas wild-type GMPPB localized to the cytoplasm, five of the identified missense mutations caused formation of aggregates in the cytoplasm or near membrane protrusions. Additionally, knockdown of the GMPPB ortholog in zebrafish caused structural muscle defects with decreased motility, eye abnormalities, and reduced glycosylation of α-DG. Together, these data indicate that GMPPB mutations are responsible for congenital and limb-girdle muscular dystrophies with hypoglycosylation of α-DG. PMID:23768512

  11. [Updates in muscular dystrophies].

    PubMed

    Erazo-Torricelli, R

    Advances in molecular genetics on lasts 15 years had modified profoundly our knowledge about muscular dystrophies. The pathogenia, caused by defectives proteins which disrupt dystrophin-associated-protein complex in most of the dystrophies, has generate a new classification based in protein and genomic defects. In this review, clinical, genetic, diagnostic and therapeutic aspects of the main muscular dystrophies are described. Limb girdle muscular dystrophies with Duchenne-like phenotype (sarcoglycanopathies), are identified by immunohistochemistry, as X-linked Emery-Dreifuss muscular dystrophy (emerin deficit), and classical congenital muscular dystrophy (merosine depletion). The others limb girdle muscular dystrophies, an heterogeneous phenotypical group, are detected by Western blot (mainly calpainopathies), or inmunohistochemistry in muscle (caveolinopathies) and blood (dysferlinopathies). Congenital muscular dystrophies with brain malformations: Fukuyama, muscle-eye-brain, and Walker-Warburg syndrome; and fukutin-related protein dystrophy, only may be differentiated by genetic analysis. All them shows alpha-dystroglican depletion. Autosomal dominant Emery-Dreifuss muscular dystrophy and facioscapulohumeral dystrophy are exclusively identified by DNA study. Finally, Duchenne/Becker muscular dystrophies are diagnosed by immunohistochemistry, Western blot and/or DNA analysis. Treatment of muscular dystrophies is based in physiotherapy, ventilatory support, surgery and drugs (mainly steroids, effective in Duchenne/Becker muscular dystrophies). Genic and cellular therapy are yet on experimental field, and are matter of the future. Now, accurate diagnosis is important for therapeutic management, prognosis and genetic counseling.

  12. The Marshall M. Parks memorial lecture: making sense of early-onset childhood retinal dystrophies--the clinical phenotype of Leber congenital amaurosis.

    PubMed

    Traboulsi, E I

    2010-10-01

    A correct diagnosis of the early-onset childhood retinal dystrophies requires careful clinical evaluation, the detection of suggestive or pathognomonic ophthalmoscopic clues, the use of electrophysiology to document characteristic electroretinographic findings and, in some cases, the utilisation of newer diagnostic modalities such as optical coherence tomography. Molecular diagnosis confirms the clinical diagnosis and provides the basis for possible future gene therapy. A strict definition of early-onset childhood retinal dystrophies (EOCRDs) does not exist, but inherited retinal dystrophies that are diagnosed in the first few years of life could be included under this umbrella terminology. The clinical ophthalmological manifestations of these diseases may or may not be detected at birth, and include the triad of severe vision loss, sensory nystagmus and electroretinographic abnormalities. Their clinical manifestations are light sensitivity, night blindness, fundus pigmentary changes and other psychophysical and retinal anatomic abnormalities. Diseases that could be included in the EOCRDs are Leber congenital amaurosis, achromatopsia, congenital stationary night blindness, X-linked juvenile retinoschisis, Goldmann-Favre disease and other NR2E3-related disorders, and possibly some very early-onset forms of Stargardt disease and juvenile retinitis pigmentosa. In this paper, phenotypic clues to the diagnosis of the underlying molecular defect in patients with Leber congenital amaurosis are discussed and an overview of the clinical workup of the child with a retinal dystrophy is presented. An accurate diagnosis of individual EOCRD allows a better prediction of the clinical course and the planning of possible and emerging therapies.

  13. Melanocytes from Patients Affected by Ullrich Congenital Muscular Dystrophy and Bethlem Myopathy have Dysfunctional Mitochondria That Can be Rescued with Cyclophilin Inhibitors.

    PubMed

    Zulian, Alessandra; Tagliavini, Francesca; Rizzo, Erika; Pellegrini, Camilla; Sardone, Francesca; Zini, Nicoletta; Maraldi, Nadir Mario; Santi, Spartaco; Faldini, Cesare; Merlini, Luciano; Petronilli, Valeria; Bernardi, Paolo; Sabatelli, Patrizia

    2014-01-01

    Ullrich congenital muscular dystrophy and Bethlem myopathy are caused by mutations in collagen VI (ColVI) genes, which encode an extracellular matrix protein; yet, mitochondria play a major role in disease pathogenesis through a short circuit caused by inappropriate opening of the permeability transition pore, a high-conductance channel, which causes a shortage in ATP production. We find that melanocytes do not produce ColVI yet they bind it at the cell surface, suggesting that this protein may play a trophic role and that its absence may cause lesions similar to those seen in skeletal muscle. We show that mitochondria in melanocytes of Ullrich congenital muscular dystrophy and Bethlem myopathy patients display increased size, reduced matrix density, and disrupted cristae, findings that suggest a functional impairment. In keeping with this hypothesis, mitochondria (i) underwent anomalous depolarization after inhibition of the F-ATP synthase with oligomycin, and (ii) displayed decreased respiratory reserve capacity. The non-immunosuppressive cyclophilin inhibitor NIM811 prevented mitochondrial depolarization in response to oligomycin in melanocytes from both Ullrich congenital muscular dystrophy and Bethlem myopathy patients, and partially restored the respiratory reserve of melanocytes from one Bethlem myopathy patient. These results match our recent findings on melanocytes from patients affected by Duchenne muscular dystrophy (Pellegrini et al., 2013), and suggest that skin biopsies may represent a minimally invasive tool to investigate mitochondrial dysfunction and to evaluate drug efficacy in ColVI-related myopathies and possibly in other muscle wasting conditions like aging sarcopenia.

  14. YAC and cosmid contigs encompassing the Fukuyama-type congenital muscular dystrophy (FCMD) candidate region on 9q31

    SciTech Connect

    Miyake, Masashi; Nakahori, Yutaka; Matsushita, Ikumi

    1997-03-01

    Fukuyama-type congenital muscular dystrophy (FCMD), the second most common form of childhood muscular dystrophy in Japan, is an autosomal recessive severe muscular dystrophy associated with an anomaly of the brain. We had mapped the FCMD gene to an approximately 5-cM interval between D9S127 and D9S2111 on 9q31-q33 and had also found evidence for linkage disequilibrium between FCMD and D9S306 in this candidate region. Through further analysis, we have defined another marker, D9S172, which showed stronger linkage disequilibrium than D9S306. A yeast artificial chromosome (YAC) contig spanning 3.5 Mb, which includes this D9S306-D9S172 interval on 9q31, has been constructed by a combination of sequence-tagged site, Alu-PCR, and restriction mapping. Also, cosmid clones subcloned from the YAC were assembled into three contigs, one of which contains D9S2107, which showed the strongest linkage disequilibrium with FCMD. These contigs also allowed us to order the markers as follows: cen-D9S127-({approximately}800 kb)-D9S306 (identical to D9S53)-({approximately}700 kb)-A107XF9-({approximately}500 kb)-D9S172-({approximately}30 kb)-D9S299 (identical to D9S774)-({approximately}120 kb)-WI2269-tel. Thus, we have constructed the first high-resolution physical map of the FCMD candidate region. The YAC and cosmid contigs established here will be a crucial resource for identification of the FCMD gene and other genes in this region. 37 refs., 7 figs., 2 tabs.

  15. Primary, congenital neuroaxonal dystrophy with peripheral nerve demyelination in Merino-Border Leicester × Polled Dorset lambs.

    PubMed

    Hawes, M C; Finnie, J W; Jerrett, I V; Badman, R; Scott, M

    2017-09-13

    Clinicopathological features of neuroaxonal dystrophy (NAD) in newborn, Merino-Border Leicester × Polled Dorset lambs are described. The affected lambs were unable to walk at birth and microscopic examination of brainstem and spinal cord sections revealed bilaterally symmetrical accumulations of axonal swellings (spheroids), the histological hallmark of primary NAD. The neurological deficit was also exacerbated by myelin loss and secondary axonal degeneration, particularly in the spinal cord and sciatic nerves, but also, to a more limited extent, in brainstem and spinal nerves. Although lambs previously diagnosed with NAD have ranged in age from 2 days to 7 months, this is believed to be the first report of congenital NAD in this species. Moreover, the present cases are the only ones in which peripheral nerve demyelination has been found. © 2017 Australian Veterinary Association.

  16. A Novel Lamin A Mutant Responsible for Congenital Muscular Dystrophy Causes Distinct Abnormalities of the Cell Nucleus.

    PubMed

    Barateau, Alice; Vadrot, Nathalie; Vicart, Patrick; Ferreiro, Ana; Mayer, Michèle; Héron, Delphine; Vigouroux, Corinne; Buendia, Brigitte

    2017-01-01

    A-type lamins, the intermediate filament proteins participating in nuclear structure and function, are encoded by LMNA. LMNA mutations can lead to laminopathies such as lipodystrophies, premature aging syndromes (progeria) and muscular dystrophies. Here, we identified a novel heterozygous LMNA p.R388P de novo mutation in a patient with a non-previously described severe phenotype comprising congenital muscular dystrophy (L-CMD) and lipodystrophy. In culture, the patient's skin fibroblasts entered prematurely into senescence, and some nuclei showed a lamina honeycomb pattern. C2C12 myoblasts were transfected with a construct carrying the patient's mutation; R388P-lamin A (LA) predominantly accumulated within the nucleoplasm and was depleted at the nuclear periphery, altering the anchorage of the inner nuclear membrane protein emerin and the nucleoplasmic protein LAP2-alpha. The mutant LA triggered a frequent and severe nuclear dysmorphy that occurred independently of prelamin A processing, as well as increased histone H3K9 acetylation. Nuclear dysmorphy was not significantly improved when transfected cells were treated with drugs disrupting microtubules or actin filaments or modifying the global histone acetylation pattern. Therefore, releasing any force exerted at the nuclear envelope by the cytoskeleton or chromatin did not rescue nuclear shape, in contrast to what was previously shown in Hutchinson-Gilford progeria due to other LMNA mutations. Our results point to the specific cytotoxic effect of the R388P-lamin A mutant, which is clinically related to a rare and severe multisystemic laminopathy phenotype.

  17. Lethal congenital muscular dystrophy in two sibs with arthrogryposis multiplex: new entity or variant of cobblestone lissencephaly syndrome?

    PubMed

    Seidahmed, M Z; Sunada, Y; Ozo, C O; Hamid, F; Campbell, K P; Salih, M A

    1996-12-01

    We report on two sisters of first degree cousin parents who were born with severe hypotonia, arthrogryposis multiplex congenita (AMC) and dysmorphic features consistent with the fetal akinesia/hypokinesia sequence. They needed assisted ventilation and each died at the age of 5 months. Both had type II lissencephaly (cobblestone lissencephaly) which was visualized by magnetic resonance imaging (MRI) in the proband. Ophthalmic evaluation revealed no ocular malformations in either of them. Brain auditory evoked potentials (BAEP) revealed bilateral severe sensorineural hearing loss in the proband, whereas an MRI-guided open muscle biopsy of the sartorius muscle (the only remaining thigh muscle) showed features of muscular dystrophy. Immunohistochemistry revealed normal dystrophin, dystrophin-associated glycoproteins (DAG) and merosin. Certain clinical and pathological features distinguish the disease seen in these sisters from reported isolated cases where lethal AMC was associated with brain dysplasia and from the main syndromes of congenital muscular dystrophy/cobblestone lissencephaly. Differences from the Walker-Warburg syndrome, which simulates it in severity, included the absence of severe hydrocephalus, normal creatine kinase (for age) and minimal (mainly periventricular) white matter abnormalities. The findings suggest either an independent entity, in the studied family, or an allelic variation of the cobblestone lissencephaly (type II lissencephaly) syndrome.

  18. A case of merosin-negative congenital muscular dystrophy with extensive white matter abnormalities and electroencephalographic changes in a Syrian boy.

    PubMed

    Al-Ajmi, M O; Abdulla, J K; Neubauer, D

    2001-01-01

    Congenital muscular dystrophies are a group of heterogeneous disorders inherited as an autosomal recessive disease. In the Caucasians they are most frequently encountered as the so-called "pure" or occidental form. Recently it has been found that the severity of concomitant white matter changes depends on the presence or absence of merosin, the laminin isoform, in the skeletal muscle. The authors present a 2-year-old Syrian boy with congenital muscular dystrophy which proved to be merosin (laminin alpha2) deficient and believe that this is the first case described from Syria. The clinical picture, biochemical findings, neurophysiological investigations, biopsy findings and extensive abnormalities of white matter on magnetic resonance imaging (MRI) found in this case are presented. Peculiar electroencephalographic (EEG) pattern with fast rhythms in occipito-temporal regions is emphasized.

  19. Therapeutic advances in muscular dystrophy

    PubMed Central

    Leung, Doris G; Wagner, Kathryn R

    2013-01-01

    The muscular dystrophies comprise a heterogeneous group of genetic disorders that produce progressive skeletal muscle weakness and wasting. There has been rapid growth and change in our understanding of these disorders in recent years, and advances in basic science are being translated into increasing numbers of clinical trials. This review will discuss therapeutic developments in 3 of the most common forms of muscular dystrophy: Duchenne muscular dystrophy, facioscapulohumeral muscular dystrophy, and myotonic dystrophy. Each of these disorders represents a different class of genetic disease (monogenic, epigenetic, and repeat expansion disorders), and the approach to therapy addresses the diverse and complex molecular mechanisms involved in these diseases. The large number of novel pharmacologic agents in development with good biologic rationale and strong proof of concept suggests there will be an improved quality of life for individuals with muscular dystrophy. PMID:23939629

  20. A Novel Lamin A Mutant Responsible for Congenital Muscular Dystrophy Causes Distinct Abnormalities of the Cell Nucleus

    PubMed Central

    Barateau, Alice; Vadrot, Nathalie; Vicart, Patrick; Ferreiro, Ana; Mayer, Michèle; Héron, Delphine; Vigouroux, Corinne

    2017-01-01

    A-type lamins, the intermediate filament proteins participating in nuclear structure and function, are encoded by LMNA. LMNA mutations can lead to laminopathies such as lipodystrophies, premature aging syndromes (progeria) and muscular dystrophies. Here, we identified a novel heterozygous LMNA p.R388P de novo mutation in a patient with a non-previously described severe phenotype comprising congenital muscular dystrophy (L-CMD) and lipodystrophy. In culture, the patient’s skin fibroblasts entered prematurely into senescence, and some nuclei showed a lamina honeycomb pattern. C2C12 myoblasts were transfected with a construct carrying the patient’s mutation; R388P-lamin A (LA) predominantly accumulated within the nucleoplasm and was depleted at the nuclear periphery, altering the anchorage of the inner nuclear membrane protein emerin and the nucleoplasmic protein LAP2-alpha. The mutant LA triggered a frequent and severe nuclear dysmorphy that occurred independently of prelamin A processing, as well as increased histone H3K9 acetylation. Nuclear dysmorphy was not significantly improved when transfected cells were treated with drugs disrupting microtubules or actin filaments or modifying the global histone acetylation pattern. Therefore, releasing any force exerted at the nuclear envelope by the cytoskeleton or chromatin did not rescue nuclear shape, in contrast to what was previously shown in Hutchinson-Gilford progeria due to other LMNA mutations. Our results point to the specific cytotoxic effect of the R388P-lamin A mutant, which is clinically related to a rare and severe multisystemic laminopathy phenotype. PMID:28125586

  1. Omigapil treatment decreases fibrosis and improves respiratory rate in dy(2J) mouse model of congenital muscular dystrophy.

    PubMed

    Yu, Qing; Sali, Arpana; Van der Meulen, Jack; Creeden, Brittany K; Gordish-Dressman, Heather; Rutkowski, Anne; Rayavarapu, Sree; Uaesoontrachoon, Kitipong; Huynh, Tony; Nagaraju, Kanneboyina; Spurney, Christopher F

    2013-01-01

    Congenital muscular dystrophy is a distinct group of diseases presenting with weakness in infancy or childhood and no current therapy. One form, MDC1A, is the result of laminin alpha-2 deficiency and results in significant weakness, respiratory insufficiency and early death. Modification of apoptosis is one potential pathway for therapy in these patients. dy(2J) mice were treated with vehicle, 0.1 mg/kg or 1 mg/kg of omigapil daily via oral gavage over 17.5 weeks. Untreated age matched BL6 mice were used as controls. Functional, behavioral and histological measurements were collected. dy(2J) mice treated with omigapil showed improved respiratory rates compared to vehicle treated dy(2J) mice (396 to 402 vs. 371 breaths per minute, p<0.03) and similar to control mice. There were no statistical differences in normalized forelimb grip strength between dy(2J) and controls at baseline or after 17.5 weeks and no significant differences seen among the dy(2J) treatment groups. At 30-33 weeks of age, dy(2J) mice treated with 0.1 mg/kg omigapil showed significantly more movement time and less rest time compared to vehicle treated. dy(2J) mice showed normal cardiac systolic function throughout the trial. dy(2J) mice had significantly lower hindlimb maximal (p<0.001) and specific force (p<0.002) compared to the control group at the end of the trial. There were no statistically significant differences in maximal or specific force among treatments. dy(2J) mice treated with 0.1 mg/kg/day omigapil showed decreased percent fibrosis in both gastrocnemius (p<0.03) and diaphragm (p<0.001) compared to vehicle, and in diaphragm (p<0.013) when compared to 1 mg/kg/day omigapil treated mice. Omigapil treated dy(2J) mice demonstrated decreased apoptosis. Omigapil therapy (0.1 mg/kg) improved respiratory rate and decreased skeletal and respiratory muscle fibrosis in dy(2J) mice. These results support a putative role for the use of omigapil in laminin deficient congenital muscular dystrophy

  2. Air stacking: effects on pulmonary function in patients with spinal muscular atrophy and in patients with congenital muscular dystrophy*,**

    PubMed Central

    Marques, Tanyse Bahia Carvalho; Neves, Juliana de Carvalho; Portes, Leslie Andrews; Salge, João Marcos; Zanoteli, Edmar; Reed, Umbertina Conti

    2014-01-01

    OBJECTIVE: Respiratory complications are the main causes of morbidity and mortality in patients with neuromuscular disease (NMD). The objectives of this study were to determine the effects that routine daily home air-stacking maneuvers have on pulmonary function in patients with spinal muscular atrophy (SMA) and in patients with congenital muscular dystrophy (CMD), as well as to identify associations between spinal deformities and the effects of the maneuvers. METHODS: Eighteen NMD patients (ten with CMD and eight with SMA) were submitted to routine daily air-stacking maneuvers at home with manual resuscitators for four to six months, undergoing pulmonary function tests before and after that period. The pulmonary function tests included measurements of FVC; PEF; maximum insufflation capacity (MIC); and assisted and unassisted peak cough flow (APCF and UPCF, respectively) with insufflations. RESULTS: After the use of home air-stacking maneuvers, there were improvements in the APCF and UPCF. In the patients without scoliosis, there was also a significant increase in FVC. When comparing patients with and without scoliosis, the increases in APCF and UPCF were more pronounced in those without scoliosis. CONCLUSIONS: Routine daily air-stacking maneuvers with a manual resuscitator appear to increase UPCF and APCF in patients with NMD, especially in those without scoliosis. PMID:25410841

  3. [Contiguous gene deletion syndrome in Xp21: the association between glycerol kinase deficiency, congenital suprarenal hypoplasia and Duchenne's muscular dystrophy].

    PubMed

    Pantoja-Martínez, J; Martínez-Castellano, F; Tarazona-Casany, I; Buesa-Ibáñez, E; Ardid-Encinar, M; Esparza-Sánchez, M A; Bonet-Arzo, J

    Complex glycerol kinase (GK) deficiency is a contiguous deletion of genes in Xp21 with loss of the locus for GK, for congenital adrenal hypoplasia (AHC) and/or for Duchenne's muscular dystrophy (DMD). We report the case of a 7-year-old patient with this rare disease. Our patient was a full-term male, with normal gestation and delivery, and no relevant family history. At the age of 11 days he presented a clinical picture of salt loss with lethargy, vomiting, metabolic acidosis, hypoglycaemia, hyponatraemia and hyperpotassaemia. Fluid therapy and treatment with corticoids was established. The patient's condition developed with moderate mental retardation and progressive muscular weakness. In the physical examination, the skull and face were seen to be 'hourglass' shaped. Decompensations associated to infectious processes and fasting hypoglycaemia, hydroelectrolytic disorders and ketoacidosis are all frequent. Lab findings showed a drop in cortisol levels, elevation of muscle enzymes, 'pseudohypertriglyceridaemia' and raised levels of glycerol in plasma and urine. Karyotype and neuroimaging tests were normal. A myopathic pattern was observed in the electromyogram. The genetic study confirmed the deletion in Xp21 of the genes responsible for DMD, the GK deficit and AHC. Early identification of this disease makes it possible to foresee the acute metabolic decompensations and to establish suitable genetic counselling. CK and triglyceride counts should be performed in all male patients that present a suprarenal hypoplasia; if levels are high, then it is necessary to confirm the raised glycerol values and to carry out a confirmatory genetic study.

  4. Distinct Fiber Type Signature in Mouse Muscles Expressing a Mutant Lamin A Responsible for Congenital Muscular Dystrophy in a Patient.

    PubMed

    Barateau, Alice; Vadrot, Nathalie; Agbulut, Onnik; Vicart, Patrick; Batonnet-Pichon, Sabrina; Buendia, Brigitte

    2017-04-24

    Specific mutations in LMNA, which encodes nuclear intermediate filament proteins lamins A/C, affect skeletal muscle tissues. Early-onset LMNA myopathies reveal different alterations of muscle fibers, including fiber type disproportion or prominent dystrophic and/or inflammatory changes. Recently, we identified the p.R388P LMNA mutation as responsible for congenital muscular dystrophy (L-CMD) and lipodystrophy. Here, we asked whether viral-mediated expression of mutant lamin A in murine skeletal muscles would be a pertinent model to reveal specific muscle alterations. We found that the total amount and size of muscle fibers as well as the extent of either inflammation or muscle regeneration were similar to wildtype or mutant lamin A. In contrast, the amount of fast oxidative muscle fibers containing myosin heavy chain IIA was lower upon expression of mutant lamin A, in correlation with lower expression of genes encoding transcription factors MEF2C and MyoD. These data validate this in vivo model for highlighting distinct muscle phenotypes associated with different lamin contexts. Additionally, the data suggest that alteration of muscle fiber type identity may contribute to the mechanisms underlying physiopathology of L-CMD related to R388P mutant lamin A.

  5. Body Composition, Muscle Strength, and Physical Function of Patients with Bethlem Myopathy and Ullrich Congenital Muscular Dystrophy

    PubMed Central

    Miscione, Maria Teresa; Bruno, Francesca; Ripamonti, Claudio; Nervuti, Giuliana; Orsini, Riccardo; Faldini, Cesare; Pellegrini, Massimo; Cocchi, Daniela; Merlini, Luciano

    2013-01-01

    Objective. To determine the contributions of body mass, adiposity, and muscularity to physical function and muscle strength in adult patients with Bethlem myopathy (BM) and Ullrich congenital muscular dystrophy (UCMD). Materials and Methods. Evaluation involved one UCMD and 7 BM patients. Body composition was determined by body mass index (BMI) and dual-energy-X-ray-absorptiometry (DXA), muscle strength by dynamometry, physical function by the distance walked in 6 minutes (6MWD), forced vital capacity (FVC) by a spirometer. Results. Six participants were of normal weight and 2 overweight based on BMI; all were sarcopenic based on appendicular fat free mass index (AFFMI); and 7 were sarcopenic obese based on AFFMI and % fat mass. Average muscle strength was reduced below 50% of normal. The 6MWD was in BM patients 30% less than normal. FVC was reduced in 4 of the BM patients. Muscle strength had a good correlation with the physical function variables. Correlation between muscle strength and BMI was poor; it was very high with AFFMI. AFFMI was the best single explicator of muscle strength and physical function. Conclusion. Muscle mass determined by DXA explains most of the variability of the measures of muscle strength and physical function in patients with BM and UCMD. PMID:24163611

  6. Automated genomic sequence analysis of the three collagen VI genes: applications to Ullrich congenital muscular dystrophy and Bethlem myopathy

    PubMed Central

    Lampe, A; Dunn, D; von Niederhausern, A C; Hamil, C; Aoyagi, A; Laval, S; Marie, S; Chu, M; Swoboda, K; Muntoni, F; Bonnemann, C; Flanigan, K; Bushby, K; Weiss, R

    2005-01-01

    Introduction: Mutations in the genes encoding collagen VI (COL6A1, COL6A2, and COL6A3) cause Bethlem myopathy (BM) and Ullrich congenital muscular dystrophy (UCMD). BM is a relatively mild dominantly inherited disorder with proximal weakness and distal joint contractures. UCMD is an autosomal recessive condition causing severe muscle weakness with proximal joint contractures and distal hyperlaxity. Methods: We developed a method for rapid direct sequence analysis of all 107 coding exons of the COL6 genes using single condition amplification/internal primer (SCAIP) sequencing. We have sequenced all three COL6 genes from genomic DNA in 79 patients with UCMD or BM. Results: We found putative mutations in one of the COL6 genes in 62% of patients. This more than doubles the number of identified COL6 mutations. Most of these changes are consistent with straightforward autosomal dominant or recessive inheritance. However, some patients showed changes in more than one of the COL6 genes, and our results suggest that some UCMD patients may have dominantly acting mutations rather than recessive disease. Discussion: Our findings may explain some or all of the cases of UCMD that are unlinked to the COL6 loci under a recessive model. The large number of single nucleotide polymorphisms which we generated in the course of this work may be of importance in determining the major phenotypic variability seen in this group of disorders. PMID:15689448

  7. Mutations in INPP5K Cause a Form of Congenital Muscular Dystrophy Overlapping Marinesco-Sjögren Syndrome and Dystroglycanopathy.

    PubMed

    Osborn, Daniel P S; Pond, Heather L; Mazaheri, Neda; Dejardin, Jeremy; Munn, Christopher J; Mushref, Khaloob; Cauley, Edmund S; Moroni, Isabella; Pasanisi, Maria Barbara; Sellars, Elizabeth A; Hill, R Sean; Partlow, Jennifer N; Willaert, Rebecca K; Bharj, Jaipreet; Malamiri, Reza Azizi; Galehdari, Hamid; Shariati, Gholamreza; Maroofian, Reza; Mora, Marina; Swan, Laura E; Voit, Thomas; Conti, Francesco J; Jamshidi, Yalda; Manzini, M Chiara

    2017-03-02

    Congenital muscular dystrophies display a wide phenotypic and genetic heterogeneity. The combination of clinical, biochemical, and molecular genetic findings must be considered to obtain the precise diagnosis and provide appropriate genetic counselling. Here we report five individuals from four families presenting with variable clinical features including muscular dystrophy with a reduction in dystroglycan glycosylation, short stature, intellectual disability, and cataracts, overlapping both the dystroglycanopathies and Marinesco-Sjögren syndrome. Whole-exome sequencing revealed homozygous missense and compound heterozygous mutations in INPP5K in the affected members of each family. INPP5K encodes the inositol polyphosphate-5-phosphatase K, also known as SKIP (skeletal muscle and kidney enriched inositol phosphatase), which is highly expressed in the brain and muscle. INPP5K localizes to both the endoplasmic reticulum and to actin ruffles in the cytoplasm. It has been shown to regulate myoblast differentiation and has also been implicated in protein processing through its interaction with the ER chaperone HSPA5/BiP. We show that morpholino-mediated inpp5k loss of function in the zebrafish results in shortened body axis, microphthalmia with disorganized lens, microcephaly, reduced touch-evoked motility, and highly disorganized myofibers. Altogether these data demonstrate that mutations in INPP5K cause a congenital muscular dystrophy syndrome with short stature, cataracts, and intellectual disability. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  8. European Home Mechanical Ventilation Registry

    ClinicalTrials.gov

    2016-10-25

    Pulmonary Disease, Chronic Obstructive; Amyotrophic Lateral Sclerosis; Spinal Cord Injury; Muscular Dystrophies; Obesity Hypoventilation Syndrome; Kyphoscoliosis; Congenital Central Hypoventilation Syndrome; Duchenne Muscular Dystrophy; Myopathies; Myotonic Dystrophy

  9. Possible influences on the expression of X chromosome-linked dystrophin abnormalities by heterozygosity for autosomal recessive Fukuyama congenital muscular dystrophy

    SciTech Connect

    Beggs, A.H.; Neumann, P.E.; Anderson, M.S.; Kunkel, L.M. ); Arahata, Kiichi; Arikawa, Eri; Nonaka, Ikuya )

    1992-01-15

    Abnormalities of dystrophin, a cytoskeletal protein of muscle and nerve, are generally considered specific for Duchenne and Becker muscular dystrophy. However, several patients have recently been identified with dystrophin deficiency who, before dystrophin testing, were considered to have Fukuyama congenital muscular dystrophy (FCMD) on the basis of clinical findings. Epidemiologic data suggest that only 1/3,500 males with autosomal recessive FCMD should have abnormal dystrophin. To explain the observation of 3/23 FCMD males with abnormal dystrophin, the authors propose that dystrophin and the FCMD gene product interact and that the earlier onset and greater severity of these patients' phenotype (relative to Duchenne muscular dystrophy) are due to their being heterozygous for the FCMD mutation in addition to being hemizygous for Duchenne muscular dystrophy, a genotype that is predicted to occur in 1/175,000 Japanese males. This model may help explain the genetic basis for some of the clinical and pathological variability seen among patients with FCMD, and it has potential implications for understanding the inheritance of other autosomal recessive disorders in general. For example, sex ratios for rare autosomal recessive disorders caused by mutations in proteins that interact with X chromosome-linked gene products may display predictable deviation from 1:1.

  10. Human adipose-derived stem cell transplantation as a potential therapy for collagen VI-related congenital muscular dystrophy

    PubMed Central

    2014-01-01

    Introduction Congenital muscular dystrophies (CMD) are a clinically and genetically heterogeneous group of neuromuscular disorders characterized by muscle weakness within the first two years of life. Collagen VI-related muscle disorders have recently emerged as one of the most common types of CMD. COL6 CMD is caused by deficiency and/or dysfunction of extracellular matrix (ECM) protein collagen VI. Currently, there is no specific treatment for this disabling and life-threatening disease. The primary cellular targets for collagen VI CMD therapy are fibroblasts in muscle, tendon and skin, as opposed to muscle cells for other types of muscular dystrophies. However, recent advances in stem cell research have raised the possibility that use of adult stem cells may provide dramatic new therapies for treatment of COL6 CMD. Methods Here, we developed a procedure for isolation of human stem cells from the adipose layer of neonatal skin. The adipose-derived stem cells (ADSC) were examined for expression of ECM and related genes using gene expression array analysis. The therapeutic potential of ADSC was assessed after a single intramuscular transplantation in collagen VI-deficient mice. Results Analysis of primary cultures confirmed that established ADSC represent a morphologically homogenous population with phenotypic and functional features of adult mesenchymal stem cells. A comprehensive gene expression analysis showed that ADSC express a vast array of ECM genes. Importantly, it was observed that ADSC synthesize and secrete all three collagen VI chains, suggesting suitability of ADSC for COL6 CMD treatment. Furthermore, we have found that a single intramuscular transplantation of ADSC into Col6a1−/−Rag1−/− mice under physiological and cardiotoxin-induced injury/regeneration conditions results in efficient engraftment and migration of stem cells within the skeletal muscle. Importantly, we showed that ADSC can survive long-term and continuously secrete the

  11. Facioscapulohumeral muscular dystrophy.

    PubMed

    Tawil, Rabi

    2008-10-01

    Facioscapulohumeral muscular dystrophy (FSHD), a dominantly inherited disorder, is the third most common dystrophy after Duchenne and myotonic muscular dystrophy. No known effective treatments exist for FSHD. The lack of an understanding of the underlying pathophysiology remains an obstacle in the development of targeted therapeutic interventions. The genetic defect is a loss of a critical number of a repetitive element (D4Z4) in the 4q subtelomeric region. The loss of the repeats results in specific changes in chromatin structure, although neither the molecular nor the cellular consequences of this change are known. Nevertheless, these epigenetic changes in chromatin structure offer a potential therapeutic target. This review discusses current management strategies in FSHD as well as potential therapeutic interventions to slow down or reverse the progressive muscle atrophy and weakness.

  12. Intrinsic laryngeal muscles are spared from degeneration in the dy3K/dy3K mouse model of congenital muscular dystrophy type 1A.

    PubMed

    Häger, Mattias; Durbeej, Madeleine

    2009-01-01

    Deficiency of laminin alpha2 chain leads to a severe form of congenital muscular dystrophy (MDC1A). Here, we analyzed whether the intrinsic laryngeal muscles (ILM) are spared in the dy(3K)/dy(3K) mouse model of complete laminin alpha2 chain absence. No muscle degeneration was evident; expression of various laminin chains was similar to that of limb muscles, and sustained integrin alpha7B expression was noted in laminin alpha2 chain-deficient ILM. We conclude that ILM are spared in MDC1A.

  13. Novel RDH12 mutations associated with Leber congenital amaurosis and cone-rod dystrophy: Biochemical and clinical evaluations

    PubMed Central

    Sun, Wenyu; Gerth, Christina; Maeda, Akiko; Lodowski, David T.; Van Der Kraak, Lauren; Saperstein, David A.; Héon, Elise; Palczewski, Krzysztof

    2008-01-01

    The purpose of this study was to determine the role of the retinol dehydrogenase 12 (RDH12) gene in patients affected with Leber congenital amaurosis (LCA), autosomal recessive retinitis pigmentosa (arRP) and autosomal dominant/recessive cone-rod dystrophies (CORD). Changes in the promoter region, coding regions and exon/intron junctions of the RDH12 gene were evaluated using direct DNA sequencing of patients affected with LCA (n = 36 cases), RP (n = 62) and CORD (n = 21). The allele frequency of changes observed was assessed in a multiethnic control population (n = 159 individuals). Detailed biochemical and structural modeling analysis of the observed mutations were performed to assess their biological role in the inactivation of Rdh12. A comprehensive clinical assessment of retinal structure and function in LCA patients carrying mutations in the RDH12 gene was completed. Of the six changes identified, three were novel including a homozygous C201R change in a patient affected with LCA, a heterozygous A177V change in patients affected with CORD and a heterozygous G46G change in a patient affected with LCA. A novel compound heterozygote T49M/A269fsX270 mutation was also found in a patient with LCA, and both homozygous and heterozygous R161Q changes were seen in 26 patients affected with LCA, CORD or RP. These R161Q, G46G and the A177V sequence changes were shown to be polymorphic. We found that Rdh12 mutant proteins associated with LCA were inactive or displayed only residual activity when expressed in COS-7 and Sf9 cells, whereas those mutants that were considered polymorphisms were fully active. Thus, impairment of retinal structure and function for patients carrying these mutations correlated with the biochemical properties of the mutants. PMID:17512964

  14. Comprehensive target capture/next-generation sequencing as a second-tier diagnostic approach for congenital muscular dystrophy in Taiwan.

    PubMed

    Liang, Wen-Chen; Tian, Xia; Yuo, Chung-Yee; Chen, Wan-Zi; Kan, Tsu-Min; Su, Yi-Ning; Nishino, Ichizo; Wong, Lee-Jun C; Jong, Yuh-Jyh

    2017-01-01

    Congenital muscular dystrophy (CMD) is a heterogeneous disease entity. The detailed clinical manifestation and causative gene for each subgroup of CMD are quite variable. This study aims to analyze the phenotypes and genotypes of Taiwanese patients with CMD as the epidemiology of CMD varies among populations and has been scantly described in Asia. A total of 48 patients suspected to have CMD were screened and categorized by histochemistry and immunohistochemistry studies. Different genetic analyses, including next-generation sequencing (NGS), were selected, based on the clinical and pathological findings. We identified 17 patients with sarcolemma-specific collagen VI deficiency (SSCD), 6 patients with merosin deficiency, two with reduced alpha-dystroglycan staining, and two with striking lymphocyte infiltration in addition to dystrophic change on muscle pathology. Fourteen in 15 patients with SSCD, were shown to have COL6A1, COL6A2 or COL6A3 mutations by NGS analysis; all showed marked distal hyperlaxity and normal intelligence but the overall severity was less than in previously reported patients from other populations. All six patients with merosin deficiency had mutations in LAMA2. They showed relatively uniform phenotype that were compatible with previous studies, except for higher proportion of mental retardation with epilepsy. With reduced alpha-dystroglycan staining, one patient was found to carry mutations in POMT1 while another patient carried mutations in TRAPPC11. LMNA mutations were found in the two patients with inflammatory change on muscle pathology. They were clinically characterized by neck flexion limitation and early joint contracture, but no cardiac problem had developed yet. Muscle pathology remains helpful in guiding further molecular analyses by direct sequencing of certain genes or by target capture/NGS as a second-tier diagnostic tool, and is crucial for establishing the genotype-phenotype correlation. We also determined the frequencies of

  15. Protein and DNA analysis for the prenatal diagnosis of alpha2-laminin-deficient congenital muscular dystrophy.

    PubMed

    Yamamoto, Lydia U; Gollop, Thomas R; Naccache, Nadyr F; Pavanello, Rita C M; Zanoteli, Edmar; Zatz, Mayana; Vainzof, Mariz

    2004-09-01

    Congenital muscular dystrophies (CMD) are characterized by neonatal hypotonia and/or artrogriposis associated with a dystrophic muscle biopsy. The CMD1A form is caused by a deficiency of the alpha2 chain of laminin 2 (LAMA2 gene at 6q2), a protein present in the basal lamina of muscle fibers, in Schwann cells, epidermis, and in fetal trophoblastic tissue. This allows its study for prenatal diagnosis in the chorionic villous (CV), which was performed in a family with one deceased affected CMD1A child. Immunohistochemical analysis of the CV using antibodies against the C- and N-terminal domains of the alpha2-laminin protein showed a normal positive labeling for both antibodies in the "at-risk" CV, which did not differ from the normal control CV. The integrity of the CV membrane was confirmed through the analysis with antibodies against alpha1, beta1, and gamma1 laminins. DNA study using markers flanking the 6q2 region showed that the affected patient and the "at-risk" fetus did not share the same haplotype. Therefore, the fetus was considered normal through both methodologies, which was confirmed after the birth of a clinically normal male baby. As the LAMA2 gene is very large and the spectrum of mutations causing disease is wide, the analysis of the protein in muscle biopsy has been largely used for the diagnosis. Besides, the possibility to detect it in the chorionic villous, mainly using positive markers, also offers a powerful tool for prenatal diagnosis.

  16. Alternative splicing and muscular dystrophy

    PubMed Central

    Pistoni, Mariaelena; Ghigna, Claudia; Gabellini, Davide

    2013-01-01

    Alternative splicing of pre-mRNAs is a major contributor to proteomic diversity and to the control of gene expression in higher eukaryotic cells. For this reasons, alternative splicing is tightly regulated in different tissues and developmental stages and its disruption can lead to a wide range of human disorders. The aim of this review is to focus on the relevance of alternative splicing for muscle function and muscle disease. We begin by giving a brief overview of alternative splicing, muscle-specific gene expression and muscular dystrophy. Next, to illustrate these concepts we focus on two muscular dystrophy, myotonic muscular dystrophy and facioscapulohumeral muscular dystrophy, both associated to disruption of splicing regulation in muscle. PMID:20603608

  17. Molecular and Genetic Studies of Congenital Myopathies

    ClinicalTrials.gov

    2016-12-08

    Central Core Disease; Centronuclear Myopathy; Congenital Fiber Type Disproportion; Multiminicore Disease; Myotubular Myopathy; Nemaline Myopathy; Rigid Spine Muscular Dystrophy; Undefined Congenital Myopathy

  18. Comprehensive target capture/next-generation sequencing as a second-tier diagnostic approach for congenital muscular dystrophy in Taiwan

    PubMed Central

    Liang, Wen-Chen; Tian, Xia; Yuo, Chung-Yee; Chen, Wan-Zi; Kan, Tsu-Min; Su, Yi-Ning; Nishino, Ichizo; Wong, Lee-Jun C.; Jong, Yuh-Jyh

    2017-01-01

    Purpose Congenital muscular dystrophy (CMD) is a heterogeneous disease entity. The detailed clinical manifestation and causative gene for each subgroup of CMD are quite variable. This study aims to analyze the phenotypes and genotypes of Taiwanese patients with CMD as the epidemiology of CMD varies among populations and has been scantly described in Asia. Methods A total of 48 patients suspected to have CMD were screened and categorized by histochemistry and immunohistochemistry studies. Different genetic analyses, including next-generation sequencing (NGS), were selected, based on the clinical and pathological findings. Results We identified 17 patients with sarcolemma-specific collagen VI deficiency (SSCD), 6 patients with merosin deficiency, two with reduced alpha-dystroglycan staining, and two with striking lymphocyte infiltration in addition to dystrophic change on muscle pathology. Fourteen in 15 patients with SSCD, were shown to have COL6A1, COL6A2 or COL6A3 mutations by NGS analysis; all showed marked distal hyperlaxity and normal intelligence but the overall severity was less than in previously reported patients from other populations. All six patients with merosin deficiency had mutations in LAMA2. They showed relatively uniform phenotype that were compatible with previous studies, except for higher proportion of mental retardation with epilepsy. With reduced alpha-dystroglycan staining, one patient was found to carry mutations in POMT1 while another patient carried mutations in TRAPPC11. LMNA mutations were found in the two patients with inflammatory change on muscle pathology. They were clinically characterized by neck flexion limitation and early joint contracture, but no cardiac problem had developed yet. Conclusion Muscle pathology remains helpful in guiding further molecular analyses by direct sequencing of certain genes or by target capture/NGS as a second-tier diagnostic tool, and is crucial for establishing the genotype-phenotype correlation. We

  19. Retinal dystrophy and congenital glaucoma as major causes of vision loss in students attending two institutions for the visually disabled in Tunis city, Tunisia.

    PubMed

    Chouchene, I; Derouiche, K; Ben Halim, N; Merdassi, A; Limaiem, R; Abdelhak, S; El Matri, L

    2014-11-01

    To assess vision loss, identify affected anatomical sites, determine etiologies and potentially avoidable causes in students attending two institutions for the visually disabled in Tunis city. A visit for a complete ophthalmological examination was performed. All students attending these schools were recruited in our study. The World Health Organisation Programme for the Prevention of Blindness (WHO/PBL) examination record for children was used. Data was analysed by the SPSS version 17 statistical software. A total of 172 students were recruited with mean age of 11.9±3.3 years (between 6 and 18 years). One hundred and thirty-seven (79.6%) were under 16 years. The sex-ratio was 1.17. Ninety students (52.3%) had low vision and eighty-two (47.7%) were blind. We reported retina (29%), whole globe (29%), globe appears normal (11%) and optic nerve (9.8%) as the common sites of ocular abnormalities. Retinal dystrophy (22.7%) and congenital glaucoma (22.7%) were the most reported ocular diseases. The main etiologies were hereditary (54.1%) and unknown (30.8%). Consanguinity was reported in 108 students (62.8%), and fifty-five students (32%) had a positive family history. Overall, 50.5% (87/172) of ocular diseases were potentially treatable or preventable. Retinal dystrophy and congenital glaucoma were the most common eye diseases. Heredity was the main etiology, and consanguinity was high. To decrease their incidence, awareness of the family members of the risks of consanguinous marriage and appropriate therapy for congenital glaucoma/cataract may significantly improve the child's visual prognosis. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  20. Muscular Dystrophy

    MedlinePlus

    ... depending on the type of muscular dystrophy. Duchenne muscular dystrophy About half of people with muscular dystrophy have ... muscles Muscle pain and stiffness Learning disabilities Becker muscular dystrophy Signs and symptoms are similar to those of ...

  1. High creatine kinase levels and white matter changes: clinical and genetic spectrum of congenital muscular dystrophies with laminin alpha-2 deficiency.

    PubMed

    Beytía, Maria de los Angeles; Dekomien, Gabriele; Hoffjan, Sabine; Haug, Verena; Anastasopoulos, Constantin; Kirschner, Janbernd

    2014-08-01

    Primary deficiency of laminin alpha-2 due to mutations in the LAMA2 gene accounts for 30% of all patients with congenital muscular dystrophy. Here, we present seven patients with partial or total laminin alpha-2 deficiency (MDC1A) with a wide clinical spectrum, ranging from ambulant patients to patients who were never able to stand or sit. We identified two pathogenic mutations in the LAMA2 gene in all patients except for one patient in whom only one mutation was found. Six of the mutations were previously undescribed. In some of the milder cases, laminin alpha-2 expression in the muscle biopsy was only slightly reduced. These findings emphasize that analysis of the LAMA2 gene might be necessary in patients with muscle weakness, cerebral white matter changes and high creatine kinase levels, even in the presence of laminin alpha-2 in the muscle biopsy. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Novel Use of Tolvaptan in a Pediatric Patient With Congestive Heart Failure Due to Duchenne Muscular Dystrophy and Congenital Adrenal Hyperplasia.

    PubMed

    Sami, Sarah A; Moffett, Brady S; Karlsten, Melissa L; Cabrera, Antonio G; Price, Jack F; Dreyer, William J; Denfield, Susan W; Jeewa, Aamir

    2015-01-01

    Successful management of hyponatremia in heart failure patients requires a multifaceted approach in order to preserve end-organ function. We describe the novel use of a selective vasopressin receptor antagonist, tolvaptan, for management of hyponatremia in a 17-year-old Caucasian male with severe Duchenne muscular dystrophy, congestive heart failure (CHF), and congenital adrenal hyperplasia. The medical history was significant for recurrent admissions for hyponatremia secondary to adrenal crises, which was also exacerbated by his CHF. After initiation of tolvaptan and its extended administration, he had no further hyponatremia-related admissions and no adverse reactions. The complexity of this combination of conditions is presented, and the efficacy of the drug and the rationale behind the treatment approach is discussed.

  3. Muscle Weakness and Fibrosis Due to Cell Autonomous and Non-cell Autonomous Events in Collagen VI Deficient Congenital Muscular Dystrophy.

    PubMed

    Noguchi, Satoru; Ogawa, Megumu; Malicdan, May Christine; Nonaka, Ikuya; Nishino, Ichizo

    2017-02-01

    Congenital muscular dystrophies with collagen VI deficiency are inherited muscle disorders with a broad spectrum of clinical presentation and are caused by mutations in one of COL6A1-3 genes. Muscle pathology is characterized by fiber size variation and increased interstitial fibrosis and adipogenesis. In this study, we define critical events that contribute to muscle weakness and fibrosis in a mouse model with collagen VI deficiency. The Col6a1(GT/GT) mice develop non-progressive weakness from younger age, accompanied by stunted muscle growth due to reduced IGF-1 signaling activity. In addition, the Col6a1(GT/GT) mice have high numbers of interstitial skeletal muscle mesenchymal progenitor cells, which dramatically increase with repeated myofiber necrosis/regeneration. Our results suggest that impaired neonatal muscle growth and the activation of the mesenchymal cells in skeletal muscles contribute to the pathology of collagen VI deficient muscular dystrophy, and more importantly, provide the insights on the therapeutic strategies for collagen VI deficiency.

  4. Retinal ectopias and mechanically weakened basement membrane in a mouse model of muscle-eye-brain (MEB) disease congenital muscular dystrophy.

    PubMed

    Hu, Huaiyu; Candiello, Joseph; Zhang, Peng; Ball, Sherry L; Cameron, David A; Halfter, Willi

    2010-07-28

    Some forms of congenital muscular dystrophy are associated with cortical and retinal dysplasias. Protein O-mannose N-acetylglucosaminyltransferase 1 (POMGnT1) knockout mice, one of the mouse models of muscular dystrophy, exhibit a thinner retina with reduced density of retinal ganglion cells. This study is aimed to further characterize the knockout retina, with special emphasis on the inner limiting membrane, the basement membrane of the retina. Immunofluorescence staining and transmission electron microscopy were used to analyze the retinas. Atomic force microscopy was performed on the inner limiting membrane preparations to examine their mechanical properties. The inner limiting membrane of the knockout mice exhibited frequent breaks with protrusions of the Müller glial processes and ectopic placement of retinal ganglion cells into the vitreous humor. Disruptions in inner limiting membrane integrity developmentally precede the cellular abnormalities. Regions of disrupted inner limiting membrane were also associated with molecular abnormalities of Müller glia that included diminished presence of the integral membrane proteins Kir4.1 (an inwardly rectifying potassium channel) and aquaporin-4. When measured with atomic force microscopy, the POMGnT1 knockout mouse inner limiting membrane (ILM) exhibited significantly reduced Young's modulus and is therefore mechanically weaker than the ILM from controls. Deficiency of POMGnT1-mediated glycosylation of dystroglycan is implicated in reduced stiffness of the ILM. The weakened ILM results in the disruption of the membrane and subsequent reduction in retinal integrity.

  5. Collagen VI microfibril formation is abolished by an {alpha}2(VI) von Willebrand factor type A domain mutation in a patient with Ullrich congenital muscular dystrophy.

    PubMed

    Tooley, Leona D; Zamurs, Laura K; Beecher, Nicola; Baker, Naomi L; Peat, Rachel A; Adams, Naomi E; Bateman, John F; North, Kathryn N; Baldock, Clair; Lamandé, Shireen R

    2010-10-22

    Collagen VI is an extracellular protein that most often contains the three genetically distinct polypeptide chains, α1(VI), α2(VI), and α3(VI), although three recently identified chains, α4(VI), α5(VI), and α6(VI), may replace α3(VI) in some situations. Each chain has a triple helix flanked by N- and C-terminal globular domains that share homology with the von Willebrand factor type A (VWA) domains. During biosynthesis, the three chains come together to form triple helical monomers, which then assemble into dimers and tetramers. Tetramers are secreted from the cell and align end-to-end to form microfibrils. The precise molecular mechanisms responsible for assembly are unclear. Mutations in the three collagen VI genes can disrupt collagen VI biosynthesis and matrix organization and are the cause of the inherited disorders Bethlem myopathy and Ullrich congenital muscular dystrophy. We have identified a Ullrich congenital muscular dystrophy patient with compound heterozygous mutations in α2(VI). The first mutation causes skipping of exon 24, and the mRNA is degraded by nonsense-mediated decay. The second mutation is a two-amino acid deletion in the C1 VWA domain. Recombinant C1 domains containing the deletion are insoluble and retained intracellularly, indicating that the mutation has detrimental effects on domain folding and structure. Despite this, mutant α2(VI) chains retain the ability to associate into monomers, dimers, and tetramers. However, we show that secreted mutant tetramers containing structurally abnormal C1 VWA domains are unable to associate further into microfibrils, directly demonstrating the critical importance of a correctly folded α2(VI) C1 domain in microfibril formation.

  6. A Novel Missense Mutation in POMT1 Modulates the Severe Congenital Muscular Dystrophy Phenotype Associated with POMT1 Nonsense Mutations

    PubMed Central

    Wallace, Stephanie E.; Conta, Jessie H.; Winder, Thomas L.; Willer, Tobias; Eskuri, Jamie M.; Haas, Richard; Patterson, Kathleen; Campbell, Kevin P.; Moore, Steven A.; Gospe, Sidney M.

    2014-01-01

    Mutations in POMT1 lead to a group of neuromuscular conditions ranging in severity from Walker-Warburg syndrome to limb girdle muscular dystrophy. We report two male siblings, ages 19 and 14, and an unrelated 6-year old female with early onset muscular dystrophy and intellectual disability with minimal structural brain anomalies and no ocular abnormalities. Compound heterozygous mutations in POMT1 were identified including a previously reported nonsense mutation (c.2167dupG; p.Asp723Glyfs*8) associated with Walker-Warburg syndrome and a novel missense mutation in a highly conserved region of the protein O-mannosyltransferase 1 protein (c.1958C>T; p.Pro653Leu). This novel variant reduces the phenotypic severity compared to patients with homozygous c.2167dupG mutations or compound heterozygous patients with a c.2167dupG mutation and a wide range of other mutant POMT1 alleles. PMID:24491487

  7. Highly efficient in vivo delivery of PMO into regenerating myotubes and rescue in laminin-α2 chain-null congenital muscular dystrophy mice.

    PubMed

    Aoki, Yoshitsugu; Nagata, Tetsuya; Yokota, Toshifumi; Nakamura, Akinori; Wood, Matthew J A; Partridge, Terence; Takeda, Shin'ichi

    2013-12-15

    Phosphorodiamidate morpholino oligomer (PMO)-mediated exon skipping is among the more promising approaches to the treatment of several neuromuscular disorders including Duchenne muscular dystrophy. The main weakness of this approach arises from the low efficiency and sporadic nature of the delivery of charge-neutral PMO into muscle fibers, the mechanism of which is unknown. In this study, to test our hypothesis that muscle fibers take up PMO more efficiently during myotube formation, we induced synchronous muscle regeneration by injection of cardiotoxin into the tibialis anterior muscle of Dmd exon 52-deficient mdx52 and wild-type mice. Interestingly, by in situ hybridization, we detected PMO mainly in embryonic myosin heavy chain-positive regenerating fibers. In addition, we showed that PMO or 2'-O-methyl phosphorothioate is taken up efficiently into C2C12 myotubes when transfected 24-72 h after the induction of differentiation but is poorly taken up into undifferentiated C2C12 myoblasts suggesting efficient uptake of PMO in the early stages of C2C12 myotube formation. Next, we tested the therapeutic potential of PMO for laminin-α2 chain-null dy(3K)/dy(3K) mice: a model of merosin-deficient congenital muscular dystrophy (MDC1A) with active muscle regeneration. We confirmed the recovery of laminin-α2 chain and slightly prolonged life span following skipping of the mutated exon 4 in dy(3K)/dy(3K) mice. These findings support the idea that PMO entry into fibers is dependent on a developmental stage in myogenesis rather than on dystrophinless muscle membranes and provide a platform for developing PMO-mediated therapies for a variety of muscular disorders, such as MDC1A, that involve active muscle regeneration.

  8. Laminin-111 Protein Therapy Reduces Muscle Pathology and Improves Viability of a Mouse Model of Merosin-Deficient Congenital Muscular Dystrophy

    PubMed Central

    Rooney, Jachinta E.; Knapp, Jolie R.; Hodges, Bradley L.; Wuebbles, Ryan D.; Burkin, Dean J.

    2012-01-01

    Merosin-deficient congenital muscular dystrophy type 1A (MDC1A) is a lethal muscle-wasting disease that is caused by mutations in the LAMA2 gene, resulting in the loss of laminin-α2 protein. MDC1A patients exhibit severe muscle weakness from birth, are confined to a wheelchair, require ventilator assistance, and have reduced life expectancy. There are currently no effective treatments or cures for MDC1A. Laminin-α2 is required for the formation of heterotrimeric laminin-211 (ie, α2, β1, and γ1) and laminin-221 (ie, α2, β2, and γ1), which are major constituents of skeletal muscle basal lamina. Laminin-111 (ie, α1, β1, and γ1) is the predominant laminin isoform in embryonic skeletal muscle and supports normal skeletal muscle development in laminin-α2–deficient muscle but is absent from adult skeletal muscle. In this study, we determined whether treatment with Engelbreth-Holm-Swarm–derived mouse laminin-111 protein could rescue MDC1A in the dyW−/− mouse model. We demonstrate that laminin-111 protein systemically delivered to the muscles of laminin-α2–deficient mice prevents muscle pathology, improves muscle strength, and dramatically increases life expectancy. Laminin-111 also prevented apoptosis in laminin-α2–deficient mouse muscle and primary human MDC1A myogenic cells, which indicates a conserved mechanism of action and cross-reactivity between species. Our results demonstrate that laminin-111 can serve as an effective protein substitution therapy for the treatment of muscular dystrophy in the dyW−/− mouse model and establish the potential for its use in the treatment of MDC1A. PMID:22322301

  9. Angiotensin II type 1 receptor antagonists alleviate muscle pathology in the mouse model for laminin-α2-deficient congenital muscular dystrophy (MDC1A)

    PubMed Central

    2012-01-01

    Background Laminin-α2-deficient congenital muscular dystrophy (MDC1A) is a severe muscle-wasting disease for which no curative treatment is available. Antagonists of the angiotensin II receptor type 1 (AT1), including the anti-hypertensive drug losartan, have been shown to block also the profibrotic action of transforming growth factor (TGF)-β and thereby ameliorate disease progression in mouse models of Marfan syndrome. Because fibrosis and failure of muscle regeneration are the main reasons for the severe disease course of MDC1A, we tested whether L-158809, an analog derivative of losartan, could ameliorate the dystrophy in dyW/dyW mice, the best-characterized model of MDC1A. Methods L-158809 was given in food to dyW/dyW mice at the age of 3 weeks, and the mice were analyzed at the age of 6 to 7 weeks. We examined the effect of L-158809 on muscle histology and on muscle regeneration after injury as well as the locomotor activity and muscle strength of the mice. Results We found that TGF-β signaling in the muscles of the dyW/dyW mice was strongly increased, and that L-158809 treatment suppressed this signaling. Consequently, L-158809 reduced fibrosis and inflammation in skeletal muscle of dyW/dyW mice, and largely restored muscle regeneration after toxin-induced injury. Mice showed improvement in their locomotor activity and grip strength, and their body weight was significantly increased. Conclusion These data provide evidence that AT1 antagonists ameliorate several hallmarks of MDC1A in dyW/dyW mice, the best-characterized mouse model for this disease. Because AT1 antagonists are well tolerated in humans and widely used in clinical practice, these results suggest that losartan may offer a potential future treatment of patients with MDC1A. PMID:22943509

  10. Laminin-111 protein therapy reduces muscle pathology and improves viability of a mouse model of merosin-deficient congenital muscular dystrophy.

    PubMed

    Rooney, Jachinta E; Knapp, Jolie R; Hodges, Bradley L; Wuebbles, Ryan D; Burkin, Dean J

    2012-04-01

    Merosin-deficient congenital muscular dystrophy type 1A (MDC1A) is a lethal muscle-wasting disease that is caused by mutations in the LAMA2 gene, resulting in the loss of laminin-α2 protein. MDC1A patients exhibit severe muscle weakness from birth, are confined to a wheelchair, require ventilator assistance, and have reduced life expectancy. There are currently no effective treatments or cures for MDC1A. Laminin-α2 is required for the formation of heterotrimeric laminin-211 (ie, α2, β1, and γ1) and laminin-221 (ie, α2, β2, and γ1), which are major constituents of skeletal muscle basal lamina. Laminin-111 (ie, α1, β1, and γ1) is the predominant laminin isoform in embryonic skeletal muscle and supports normal skeletal muscle development in laminin-α2-deficient muscle but is absent from adult skeletal muscle. In this study, we determined whether treatment with Engelbreth-Holm-Swarm-derived mouse laminin-111 protein could rescue MDC1A in the dy(W-/-) mouse model. We demonstrate that laminin-111 protein systemically delivered to the muscles of laminin-α2-deficient mice prevents muscle pathology, improves muscle strength, and dramatically increases life expectancy. Laminin-111 also prevented apoptosis in laminin-α2-deficient mouse muscle and primary human MDC1A myogenic cells, which indicates a conserved mechanism of action and cross-reactivity between species. Our results demonstrate that laminin-111 can serve as an effective protein substitution therapy for the treatment of muscular dystrophy in the dy(W-/-) mouse model and establish the potential for its use in the treatment of MDC1A.

  11. Camptocormia and dropped head syndrome as a clinic picture of myotonic myopathy.

    PubMed

    Kocaaga, Zehra; Bal, Serpil; Turan, Yasemin; Gurgan, Alev; Esmeli, Figen

    2008-12-01

    Dropped head syndrome is primarily based on weakness localized at neck extensors. It may result from motor neuron disease, myasthenia gravis, and chronic inflammatory demyelinating polyneuropathy and also from various neuromuscular diseases including inflammatory, dystrophic and metabolic myopathies. Camptocormia (CC) on the other hand is an unusual condition characterized by progressive weakness of the extensor vertebral muscles and results in involuntary trunk flexion. CC may emerge as a clinical feature of many different conditions such as several myopathies and Parkinson's disease. The association of dropped head syndrome with CC has been rarely published in the literature. However, this is the only case presenting with concomitant dropped head syndrome and CC as a clinical picture of myotonic dystrophy (MD). In this report we aimed to represent a female patient, who was diagnosed as having myotonic dystrophy, with concurrent dropped head syndrome and CC.

  12. A novel missense mutation in POMT1 modulates the severe congenital muscular dystrophy phenotype associated with POMT1 nonsense mutations.

    PubMed

    Wallace, Stephanie E; Conta, Jessie H; Winder, Thomas L; Willer, Tobias; Eskuri, Jamie M; Haas, Richard; Patterson, Kathleen; Campbell, Kevin P; Moore, Steven A; Gospe, Sidney M

    2014-04-01

    Mutations in POMT1 lead to a group of neuromuscular conditions ranging in severity from Walker-Warburg syndrome to limb girdle muscular dystrophy. We report two male siblings, ages 19 and 14, and an unrelated 6-year old female with early onset muscular dystrophy and intellectual disability with minimal structural brain anomalies and no ocular abnormalities. Compound heterozygous mutations in POMT1 were identified including a previously reported nonsense mutation (c.2167dupG; p.Asp723Glyfs*8) associated with Walker-Warburg syndrome and a novel missense mutation in a highly conserved region of the protein O-mannosyltransferase 1 protein (c.1958C>T; p.Pro653Leu). This novel variant reduces the phenotypic severity compared to patients with homozygous c.2167dupG mutations or compound heterozygous patients with a c.2167dupG mutation and a wide range of other mutant POMT1 alleles. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Intracellularly-retained decorin lacking the C-terminal ear repeat causes ER stress: a cell-based etiological mechanism for congenital stromal corneal dystrophy.

    PubMed

    Chen, Shoujun; Sun, Mei; Iozzo, Renato V; Kao, Winston W-Y; Birk, David E

    2013-07-01

    Decorin, a small leucine-rich proteoglycan (SLRP), is involved in the pathophysiology of human congenital stromal corneal dystrophy (CSCD). This disease is characterized by corneal opacities and vision impairment. In reported cases, the human gene encoding decorin contains point mutations in exon 10, generating a truncated form of decorin lacking the C-terminal 33 amino acid residues. We have previously described a transgenic mouse model carrying a similar mutation in the decorin gene that leads to an ocular phenotype characterized by corneal opacities identical to CSCD in humans. We have also identified abnormal synthesis and secretion of various SLRPs in mutant mouse corneas. In the present study, we found that mutant C-terminal truncated decorin was retained in the cytoplasm of mouse keratocytes in vivo and of transfected human embryonic kidney cells. This resulted in endoplasmic reticulum stress and an unfolded protein response. Thus, we propose a novel cell-based mechanism underlying CSCD in which a truncated SLRP protein core is retained intracellularly, its accumulation triggering endoplasmic reticulum stress that results in abnormal SLRP synthesis and secretion, which ultimately affects stromal structure and corneal transparency.

  14. Targeted next generation sequencing reveals a novel intragenic deletion of the LAMA2 gene in a patient with congenital muscular dystrophy.

    PubMed

    Yang, Yun; Mao, Bing; Wang, Lixia; Mao, Liangwei; Zhou, Aifen; Cao, Jiangxia; Hu, Jiasheng; Zhou, Yan; Pan, Yanhong; Wei, Xiaoming; Yang, Shuang; Mu, Feng; Liu, Zhisheng

    2015-05-01

    Mutations in the LAMA2 gene cause laminin α‑2 (merosin)‑deficient congenital muscular dystrophies, which are autosomal recessive muscle disorders. Laminin α‑2 is widely expressed in the basement membrane of skeletal muscle, the myotendinous junctions and extra‑synaptically at neuromuscular synapses. In the present study, target next‑generation sequencing was used for mutation detection, and polymerase chain reaction (PCR) analysis and Sanger sequencing were used in the identification of small deletions. Subsequently, quantitative PCR (qPCR) was performed to characterize the identified deletion encompassing exon five of the LAMA2 gene. Two causative mutations were identified using target region sequencing which provided the additional information required to facilitate clinical diagnosis. One heterozygous mutation (p. Lys682LysfsX22) was identified and confirmed by Sanger sequencing, and another heterozygous mutation (Exon5del) was found and validated by qPCR. Co‑segregation analysis indicated that the Exon5del mutation originated from the proband's mother and the previously reported frameshift mutation (p. Lys682LysfsX22) was inherited from the proband's father. To the best of our knowledge, the present study was the first to report an entire exon five deletion in the LAMA2 gene.

  15. Magnetic Resonance Imaging Is Sensitive to Pathological Amelioration in a Model for Laminin-Deficient Congenital Muscular Dystrophy (MDC1A).

    PubMed

    Vohra, Ravneet; Accorsi, Anthony; Kumar, Ajay; Walter, Glenn; Girgenrath, Mahasweta

    2015-01-01

    To elucidate the reliability of MRI as a non-invasive tool for assessing in vivo muscle health and pathological amelioration in response to Losartan (Angiotensin II Type 1 receptor blocker) in DyW mice (mouse model for Laminin-deficient Congenital Muscular Dystrophy Type 1A). Multiparametric MR quantifications along with histological/biochemical analyses were utilized to measure muscle volume and composition in untreated and Losartan-treated 7-week old DyW mice. MRI shows that DyW mice have significantly less hind limb muscle volume and areas of hyperintensity that are absent in WT muscle. DyW mice also have significantly elevated muscle levels (suggestive of inflammation and edema). Muscle T2 returned to WT levels in response to Losartan treatment. When considering only muscle pixels without T2 elevation, DyW T2 levels are significantly lower than WT (suggestive of fibrosis) whereas Losartan-treated animals do not demonstrate this decrease in muscle T2. MRI measurements suggestive of elevated inflammation and fibrosis corroborate with increased Mac-1 positive cells as well as increased Picrosirius red staining/COL1a gene expression that is returned to WT levels in response to Losartan. MRI is sensitive to and tightly corresponds with pathological changes in DyW mice and thus is a viable and effective non-invasive tool for assessing pathological changes.

  16. Correction of a splicing defect in a mouse model of congenital muscular dystrophy type 1A using a homology-directed-repair-independent mechanism.

    PubMed

    Kemaladewi, Dwi U; Maino, Eleonora; Hyatt, Elzbieta; Hou, Huayun; Ding, Maylynn; Place, Kara M; Zhu, Xinyi; Bassi, Prabhpreet; Baghestani, Zahra; Deshwar, Amit G; Merico, Daniele; Xiong, Hui Y; Frey, Brendan J; Wilson, Michael D; Ivakine, Evgueni A; Cohn, Ronald D

    2017-08-01

    Splice-site defects account for about 10% of pathogenic mutations that cause Mendelian diseases. Prevalence is higher in neuromuscular disorders (NMDs), owing to the unusually large size and multi-exonic nature of genes encoding muscle structural proteins. Therapeutic genome editing to correct disease-causing splice-site mutations has been accomplished only through the homology-directed repair pathway, which is extremely inefficient in postmitotic tissues such as skeletal muscle. Here we describe a strategy using nonhomologous end-joining (NHEJ) to correct a pathogenic splice-site mutation. As a proof of principle, we focus on congenital muscular dystrophy type 1A (MDC1A), which is characterized by severe muscle wasting and paralysis. Specifically, we correct a splice-site mutation that causes the exclusion of exon 2 from Lama2 mRNA and the truncation of Lama2 protein in the dy(2J)/dy(2J) mouse model of MDC1A. Through systemic delivery of adeno-associated virus (AAV) carrying clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 genome-editing components, we simultaneously excise an intronic region containing the mutation and create a functional donor splice site through NHEJ. This strategy leads to the inclusion of exon 2 in the Lama2 transcript and restoration of full-length Lama2 protein. Treated dy(2J)/dy(2J) mice display substantial improvement in muscle histopathology and function without signs of paralysis.

  17. Improving Reproducibility of Phenotypic Assessments in the DyW Mouse Model of Laminin-α2 Related Congenital Muscular Dystrophy

    PubMed Central

    Willmann, Raffaella; Gordish-Dressman, Heather; Meinen, Sarina; Rüegg, Markus A.; Yu, Qing; Nagaraju, Kanneboyina; Kumar, Ayar; Girgenrath, Mahasweta; Coffey, Caroline B.M.; Cruz, Vivian; Van Ry, Pam M.; Bogdanik, Laurent; Lutz, Cathleen; Rutkowski, Anne; Burkin, Dean J.

    2017-01-01

    Laminin-α2 related Congenital Muscular Dystrophy (LAMA2-CMD) is a progressive muscle disease caused by partial or complete deficiency of laminin-211, a skeletal muscle extracellular matrix protein. In the last decade, basic science research has queried underlying disease mechanisms in existing LAMA2-CMD murine models and identified possible clinical targets and pharmacological interventions. Experimental rigor in preclinical studies is critical to efficiently and accurately quantify both negative and positive results, degree of efficiency of potential therapeutics and determine whether to move a compound forward for additional preclinical testing. In this review, we compare published available data measured to assess three common parameters in the widely used mouse model DyW, that mimics LAMA2-CMD, we quantify variability and analyse its possible sources. Finally, on the basis of this analysis, we suggest standard set of assessments and the use of available standardized protocols, to reduce variability of outcomes in the future and to improve the value of preclinical research. PMID:28550268

  18. Identification of a new locus for a peculiar form of congenital muscular dystrophy with early rigidity of the spine, on chromosome 1p35-36.

    PubMed Central

    Moghadaszadeh, B; Desguerre, I; Topaloglu, H; Muntoni, F; Pavek, S; Sewry, C; Mayer, M; Fardeau, M; Tomé, F M; Guicheney, P

    1998-01-01

    Classical congenital muscular dystrophies (CMDs) are autosomal recessive neuromuscular disorders characterized by early onset of hypotonia and weakness, atrophy of limbs and trunk muscles, contractures, and dystrophic changes in the muscle biopsy. So far, only one gene, LAMA2 (6q2), which encodes the laminin alpha2 chain (or merosin), has been identified in these disorders. Mutations in LAMA2 cause CMD with complete or partial merosin deficiency, detectable by immunocytochemistry on muscle biopsies, and account for approximately 50% of CMD cases. In a large consanguineous family (11 siblings) comprising three children affected by CMD without merosin deficiency, we undertook a genomewide search by homozygosity mapping and analyzed 380 microsatellite markers. The affected children were homozygous for several markers on chromosome 1p35-36. We identified two additional consanguineous families with affected children who also showed linkage to this locus. A maximum cumulative LOD score of 4.48, at a recombination fraction of .00, was obtained with D1S2885. A consistent feature in these three families was the presence of early rigidity of the spine, scoliosis, and reduced vital capacity, as found in rigid-spine syndrome (RSS). This study is the first description of a locus for a merosin-positive CMD and will help to better define the nosology of RSS. PMID:9585610

  19. [Macular dystrophies].

    PubMed

    Souied, E; Kaplan, J; Coscas, G; Soubrane, G

    2003-09-01

    Macular dystrophies are a group of hereditary disorders of the macula occurring in children or young adults. The most frequent in France will be presented in detail: Best disease, Stargardt macular dystrophy, cone dystrophy, X-linked retinoschisis, pattern dystrophy, and malattia leventinese. Molecular biology studies have now mapped and identified the genes involved in these macular dystrophies. Analysis of the features of fundus examination will lead to further examinations such as fluorescein angiography, indocyanine green angiography, optical coherent tomography, electroretinography, or electrooculography, in order to confirm the diagnosis. We will also present the differential diagnosis of each of these macular dystrophies.

  20. Integrins (alpha7beta1) in muscle function and survival. Disrupted expression in merosin-deficient congenital muscular dystrophy.

    PubMed Central

    Vachon, P H; Xu, H; Liu, L; Loechel, F; Hayashi, Y; Arahata, K; Reed, J C; Wewer, U M; Engvall, E

    1997-01-01

    Mutations in genes coding for dystrophin, for alpha, beta, gamma, and delta-sarcoglycans, or for the alpha2 chain of the basement membrane component merosin (laminin-2/4) cause various forms of muscular dystrophy. Analyses of integrins showed an abnormal expression and localization of alpha7beta1 isoforms in myofibers of merosin-deficient human patients and mice, but not in dystrophin-deficient or sarcoglycan-deficient humans and animals. It was shown previously that skeletal muscle fibers require merosin for survival and function (Vachon, P.H., F. Loechel, H. Xu, U.M. Wewer, and E. Engvall. 1996. J. Cell Biol. 134:1483-1497). Correction of merosin deficiency in vitro through cell transfection with the merosin alpha2 chain restored the normal localization of alpha7beta1D integrins as well as myotube survival. Overexpression of the apoptosis-suppressing molecule Bcl-2 also promoted the survival of merosin-deficient myotubes, but did not restore a normal expression of alpha7beta1D integrins. Blocking of beta1 integrins in normal myotubes induced apoptosis and severely reduced their survival. These findings (a) identify alpha7beta1D integrins as the de facto receptors for merosin in skeletal muscle; (b) indicate a merosin dependence for the accurate expression and membrane localization of alpha7beta1D integrins in myofibers; (c) provide a molecular basis for the critical role of merosin in myofiber survival; and (d) add new insights to the pathogenesis of neuromuscular disorders. PMID:9312189

  1. Substitution of a conserved cysteine-996 in a cysteine-rich motif of the laminin {alpha}2-chain in congenital muscular dystrophy with partial deficiency of the protein

    SciTech Connect

    Nissinen, M.; Xu Zhang; Tryggvason, K.

    1996-06-01

    Congenital muscular dystrophies (CMDs) are autosomal recessive muscle disorders of early onset. Approximately half of CMD patients present laminin {alpha}2-chain (merosin) deficiency in muscle biopsies, and the disease locus has been mapped to the region of the LAMA2 gene (6q22-23) in several families. Recently, two nonsense mutations in the laminin {alpha}2-chain gene were identified in CMD patients exhibiting complete deficiency of the laminin {alpha}2-chain in muscle biopsies. However, a subset of CMD patients with linkage to LAMA2 show only partial absence of the laminin {alpha}2-chain around muscle fibers, by immunocytochemical analysis. In the present study we have identified a homozygous missense mutation in the {alpha}2-chain gene of a consanguineous Turkish family with partial laminin {alpha}2-chain deficiency. The T{r_arrow}C transition at position 3035 in the cDNA sequence results in a Cys996{r_arrow}Arg substitution. The mutation that affects one of the conserved cysteine-rich repeats in the short arm of the laminin {alpha}2-chain should result in normal synthesis of the chain and in formation and secretion of a heterotrimeric laminin molecule. Muscular dysfunction is possibly caused either by abnormal disulfide cross-links and folding of the laminin repeat, leading to the disturbance of an as yet unknown binding function of the laminin {alpha}2-chain and to shorter half-life of the muscle-specific laminin-2 and laminin-4 isoforms, or by increased proteolytic sensitivity, leading to truncation of the short arm. 42 refs., 7 figs.

  2. Muscular Dystrophy

    MedlinePlus

    Muscular dystrophy (MD) is a group of more than 30 inherited diseases. They all cause muscle weakness and ... ability to walk. There is no cure for muscular dystrophy. Treatments can help with the symptoms and prevent ...

  3. Muscular dystrophy

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/001190.htm Muscular dystrophy To use the sharing features on this page, please enable JavaScript. Muscular dystrophy is a group of inherited disorders that cause ...

  4. Muscular Dystrophy

    MedlinePlus

    ... Devices The Search for a Cure en español Distrofia muscular About MD Muscular dystrophy (MD) is a ... muscles and cause different degrees of muscle weakness. Duchenne muscular dystrophy is the most common and the ...

  5. Emerging strategies for cell and gene therapy of the muscular dystrophies

    PubMed Central

    Muir, Lindsey A.; Chamberlain, Jeffrey S.

    2016-01-01

    The muscular dystrophies are a heterogeneous group of over 40 disorders that are characterised by muscle weakness and wasting. The most common are Duchenne muscular dystrophy and Becker muscular dystrophy, which result from mutations within the gene encoding dystrophin; myotonic dystrophy type 1, which results from an expanded trinucleotide repeat in the myotonic dystrophy protein kinase gene; and facioscapulohumeral dystrophy, which is associated with contractions in the subtelomeric region of human chromosome 1. Currently the only treatments involve clinical management of symptoms, although several promising experimental strategies are emerging. These include gene therapy using adeno-associated viral, lentiviral and adenoviral vectors and nonviral vectors, such as plasmid DNA. Exon-skipping and cell-based therapies have also shown promise in the effective treatment and regeneration of dystrophic muscle. The availability of numerous animal models for Duchenne muscular dystrophy has enabled extensive testing of a wide range of therapeutic approaches for this type of disorder. Consequently, we focus here on the therapeutic developments for Duchenne muscular dystrophy as a model of the types of approaches being considered for various types of dystrophy. We discuss the advantages and limitations of each therapeutic strategy, as well as prospects and recent successes in the context of future clinical applications. PMID:19555515

  6. Impaired fetal muscle development and JAK-STAT activation mark disease onset and progression in a mouse model for merosin-deficient congenital muscular dystrophy.

    PubMed

    Nunes, Andreia M; Wuebbles, Ryan D; Sarathy, Apurva; Fontelonga, Tatiana M; Deries, Marianne; Burkin, Dean J; Thorsteinsdóttir, Sólveig

    2017-06-01

    Merosin-deficient congenital muscular dystrophy type 1A (MDC1A) is a dramatic neuromuscular disease in which crippling muscle weakness is evident from birth. Here, we use the dyW mouse model for human MDC1A to trace the onset of the disease during development in utero. We find that myotomal and primary myogenesis proceed normally in homozygous dyW-/- embryos. Fetal dyW-/- muscles display the same number of myofibers as wildtype (WT) muscles, but by E18.5 dyW-/- muscles are significantly smaller and muscle size is not recovered post-natally. These results suggest that fetal dyW-/- myofibers fail to grow at the same rate as WT myofibers. Consistent with this hypothesis between E17.5 and E18.5 dyW-/- muscles display a dramatic drop in the number of Pax7- and myogenin-positive cells relative to WT muscles, suggesting that dyW-/- muscles fail to generate enough muscle cells to sustain fetal myofiber growth. Gene expression analysis of dyW-/- E17.5 muscles identified a significant increase in the expression of the JAK-STAT target gene Pim1 and muscles from 2-day and 3-week old dyW-/- mice demonstrate a dramatic increase in pSTAT3 relative to WT muscles. Interestingly, myotubes lacking integrin α7β1, a laminin-receptor, also show a significant increase in pSTAT3 levels compared with WT myotubes, indicating that α7β1 can act as a negative regulator of STAT3 activity. Our data reveal for the first time that dyW-/- mice exhibit a myogenesis defect already in utero. We propose that overactivation of JAK-STAT signaling is part of the mechanism underlying disease onset and progression in dyW-/- mice. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. [Respiratory management in muscular dystrophies].

    PubMed

    Kuru, Satoshi

    2011-11-01

    Respiratory failure is a major contributor to immobility and mortality in progressive muscular dystrophies. The severity of pulmonary impairment and the stage at which it develops differ according to the type of muscular dystrophy. Appropriate respiratory management for each type should be considered. In Duchenne muscular dystrophy (DMD), respiratory impairment manifests in the late teens, and assisted mechanical ventilation is administered. Noninvasive positive-pressure ventilation (NIPPV) has increased the median survival of patients with DMD by 10 year and improved quality of life. In myotonic dystrophy (MyD), the causes of respiratory failure can involve both the central and the peripheral nervous systems in addition to respiratory muscles. Nocturnal desaturation is more severe in MyD than in other muscular dystrophies with similar degrees of respiratory muscle weakness. Cognitive impairment should be taken into account in the management of MyD patients. NIPPV does not appear to improve survival of MyD. Guidelines for DMD have been published. Respiratory function should be assessed serially by measuring forced vital capacity, oxyhemoglobin saturation, peak cough flow, and end-tidal CO2 level. A respiratory action plan should be enacted with increasing disease severity. Therapeutic measures comprise airway clearance, respiratory muscle training, noninvasive nocturnal ventilation, daytime noninvasive ventilation, and continuous invasive ventilation. At the advanced stage of respiratory failure, attention should be paid to complications related to long-term mechanical ventilation, such as pneumothorax and tracheal hemorrhage. Discussing about end-of-life care among the patient, family, and physician is important before mechanical ventilatory support is required.

  8. Muscular Dystrophies at Different Ages: Metabolic and Endocrine Alterations

    PubMed Central

    Cruz Guzmán, Oriana del Rocío; Chávez García, Ana Laura; Rodríguez-Cruz, Maricela

    2012-01-01

    Common metabolic and endocrine alterations exist across a wide range of muscular dystrophies. Skeletal muscle plays an important role in glucose metabolism and is a major participant in different signaling pathways. Therefore, its damage may lead to different metabolic disruptions. Two of the most important metabolic alterations in muscular dystrophies may be insulin resistance and obesity. However, only insulin resistance has been demonstrated in myotonic dystrophy. In addition, endocrine disturbances such as hypogonadism, low levels of testosterone, and growth hormone have been reported. This eventually will result in consequences such as growth failure and delayed puberty in the case of childhood dystrophies. Other consequences may be reduced male fertility, reduced spermatogenesis, and oligospermia, both in childhood as well as in adult muscular dystrophies. These facts all suggest that there is a need for better comprehension of metabolic and endocrine implications for muscular dystrophies with the purpose of developing improved clinical treatments and/or improvements in the quality of life of patients with dystrophy. Therefore, the aim of this paper is to describe the current knowledge about of metabolic and endocrine alterations in diverse types of dystrophinopathies, which will be divided into two groups: childhood and adult dystrophies which have different age of onset. PMID:22701119

  9. Erythrocytes in muscular dystrophy. Investigation with 31P nuclear magnetic resonance spectroscopy

    SciTech Connect

    Sarpel, G.; Lubansky, H.J.; Danon, M.J.; Omachi, A.

    1981-05-01

    Phosphorus 31 nuclear magnetic resonance (31P NMR) signals were recorded from intact human erythrocytes for 16 hours. Total phosphate concentration, which was estimated as the sum of the individual 31P signals, was 25% lower in erythrocytes from men with myotonic dystrophy than in control erythrocytes. The inorganic-phosphate fraction contained the highest average phosphate concentration over the 16-hour period, and made the major contribution to the difference in total phosphate between the two groups. This result was not observed in erythrocytes from either women with myotonic dystrophy or patients with Duchenne's dystrophy and may be due to a change in cell membrane permeability to inorganic phosphate, which lead to lower steady-state concentrations of the intracellular phosphates.

  10. Erythrocytes in muscular dystrophy. Investigation with /sup 31/P nuclear magnetic resonance spectroscopy

    SciTech Connect

    Sarpel, G.; Lubansky, H.J.; Danon, M.J.; Omachi, A.

    1981-05-01

    Phosphorus 31 nuclear magnetic resonance (/sup 31/P NMR) signals were recorded from intact human erythrocytes for 16 hours. Total phosphate concentration, which was estimated as the sum of the individual /sup 31/P signals, was 25% lower in erythrocytes from men with myotonic dystrophy than in control erythrocytes. The inorganic-phosphate fraction contained the highest average phosphate concentration over the 16-hour period, and made the major contribution to the difference in total phosphate between the two groups. This result was not observed in erythrocytes from either women with myotonic dystrophy or patients with Duchenne's dystrophy and may be due to a change in cell membrane permeability to inorganic phosphate, which leads to lower steady-state concentrations of the intracellular phosphates.

  11. Evidence-based guideline summary: evaluation, diagnosis, and management of congenital muscular dystrophy: Report of the Guideline Development Subcommittee of the American Academy of Neurology and the Practice Issues Review Panel of the American Association of Neuromuscular & Electrodiagnostic Medicine.

    PubMed

    Kang, Peter B; Morrison, Leslie; Iannaccone, Susan T; Graham, Robert J; Bönnemann, Carsten G; Rutkowski, Anne; Hornyak, Joseph; Wang, Ching H; North, Kathryn; Oskoui, Maryam; Getchius, Thomas S D; Cox, Julie A; Hagen, Erin E; Gronseth, Gary; Griggs, Robert C

    2015-03-31

    To delineate optimal diagnostic and therapeutic approaches to congenital muscular dystrophy (CMD) through a systematic review and analysis of the currently available literature. Relevant, peer-reviewed research articles were identified using a literature search of the MEDLINE, EMBASE, and Scopus databases. Diagnostic and therapeutic data from these articles were extracted and analyzed in accordance with the American Academy of Neurology classification of evidence schemes for diagnostic, prognostic, and therapeutic studies. Recommendations were linked to the strength of the evidence, other related literature, and general principles of care. The geographic and ethnic backgrounds, clinical features, brain imaging studies, muscle imaging studies, and muscle biopsies of children with suspected CMD help predict subtype-specific diagnoses. Genetic testing can confirm some subtype-specific diagnoses, but not all causative genes for CMD have been described. Seizures and respiratory complications occur in specific subtypes. There is insufficient evidence to determine the efficacy of various treatment interventions to optimize respiratory, orthopedic, and nutritional outcomes, and more data are needed regarding complications. Multidisciplinary care by experienced teams is important for diagnosing and promoting the health of children with CMD. Accurate assessment of clinical presentations and genetic data will help in identifying the correct subtype-specific diagnosis in many cases. Multiorgan system complications occur frequently; surveillance and prompt interventions are likely to be beneficial for affected children. More research is needed to fill gaps in knowledge regarding this category of muscular dystrophies. © 2015 American Academy of Neurology.

  12. The molecular genetics of the corneal dystrophies--current status.

    PubMed

    Klintworth, Gordon K

    2003-05-01

    The pertinent literature on inherited corneal diseases is reviewed in terms of the chromosomal localization and identification of the responsible genes. Disorders affecting the cornea have been mapped to human chromosome 1 (central crystalline corneal dystrophy, familial subepithelial corneal amyloidosis, early onset Fuchs dystrophy, posterior polymorphous corneal dystrophy), chromosome 4 (Bietti marginal crystalline dystrophy), chromosome 5 (lattice dystrophy types 1 and IIIA, granular corneal dystrophy types 1, 2 and 3, Thiel-Behnke corneal dystrophy), chromosome 9 (lattice dystrophy type II), chromosome 10 (Thiel-Behnke corneal dystrophy), chromosome 12 (Meesmann dystrophy), chromosome 16 (macular corneal dystrophy, fish eye disease, LCAT disease, tyrosinemia type II), chromosome 17 (Meesmann dystrophy, Stocker-Holt dystrophy), chromosome 20 (congenital hereditary endothelial corneal dystrophy types I and II, posterior polymorphous corneal dystrophy), chromosome 21 (autosomal dominant keratoconus) and the X chromosome (cornea verticillata, cornea farinata, deep filiform corneal dystrophy, keratosis follicularis spinulosa decalvans, Lisch corneal dystrophy). Mutations in nine genes (ARSC1, CHST6, COL8A2, GLA, GSN, KRT3, KRT12, M1S1and TGFBI [BIGH3]) account for some of the corneal diseases and three of them are associated with amyloid deposition in the cornea (GSN, M1S1, TGFBI) including most of the lattice corneal dystrophies (LCDs) [LCD types I, IA, II, IIIA, IIIB, IV, V, VI and VII] recognized by their lattice pattern of linear opacities. Genetic studies on inherited diseases affecting the cornea have provided insight into some of these disorders at a basic molecular level and it has become recognized that distinct clinicopathologic phenotypes can result from specific mutations in a particular gene, as well as some different mutations in the same gene. A molecular genetic understanding of inherited corneal diseases is leading to a better appreciation of the

  13. Corneal dystrophies

    PubMed Central

    Klintworth, Gordon K

    2009-01-01

    The term corneal dystrophy embraces a heterogenous group of bilateral genetically determined non-inflammatory corneal diseases that are restricted to the cornea. The designation is imprecise but remains in vogue because of its clinical value. Clinically, the corneal dystrophies can be divided into three groups based on the sole or predominant anatomical location of the abnormalities. Some affect primarily the corneal epithelium and its basement membrane or Bowman layer and the superficial corneal stroma (anterior corneal dystrophies), the corneal stroma (stromal corneal dystrophies), or Descemet membrane and the corneal endothelium (posterior corneal dystrophies). Most corneal dystrophies have no systemic manifestations and present with variable shaped corneal opacities in a clear or cloudy cornea and they affect visual acuity to different degrees. Corneal dystrophies may have a simple autosomal dominant, autosomal recessive or X-linked recessive Mendelian mode of inheritance. Different corneal dystrophies are caused by mutations in the CHST6, KRT3, KRT12, PIP5K3, SLC4A11, TACSTD2, TGFBI, and UBIAD1 genes. Knowledge about the responsible genetic mutations responsible for these disorders has led to a better understanding of their basic defect and to molecular tests for their precise diagnosis. Genes for other corneal dystrophies have been mapped to specific chromosomal loci, but have not yet been identified. As clinical manifestations widely vary with the different entities, corneal dystrophies should be suspected when corneal transparency is lost or corneal opacities occur spontaneously, particularly in both corneas, and especially in the presence of a positive family history or in the offspring of consanguineous parents. Main differential diagnoses include various causes of monoclonal gammopathy, lecithin-cholesterol-acyltransferase deficiency, Fabry disease, cystinosis, tyrosine transaminase deficiency, systemic lysosomal storage diseases (mucopolysaccharidoses

  14. Muscular dystrophy in a dog resembling human becker muscular dystrophy.

    PubMed

    Baroncelli, A B; Abellonio, F; Pagano, T B; Esposito, I; Peirone, B; Papparella, S; Paciello, O

    2014-05-01

    A 3-year-old, male Labrador retriever dog was presented with clinical signs of progressive exercise intolerance, bilateral elbow extension, rigidity of the forelimbs, hindlimb flexion and kyphosis. Microscopical examination of muscle tissue showed marked variability in myofibre size, replacement of muscle with mature adipose tissue and degeneration/regeneration of muscle fibres, consistent with muscular dystrophy. Immunohistochemical examination for dystrophin showed markedly reduced labelling with monoclonal antibodies specific for the rod domain and the carboxy-terminal of dystrophin, while expression of β-sarcoglycan, γ-sarcoglycan and β-dystroglycan was normal. Immunoblotting revealed a truncated dystrophin protein of approximately 135 kDa. These findings supported a diagnosis of congenital canine muscular dystrophy resembling Becker muscular dystrophy in man.

  15. Muscular Dystrophy

    MedlinePlus

    ... affects about 1 out of every 3,500 boys. (Girls can carry the gene that causes the disease, ... and heart problems. Limb-girdle muscular dystrophy affects boys and girls equally. Symptoms usually start when kids are between ...

  16. Muscular Dystrophy

    MedlinePlus

    ... It Like for Teens With MD? en español Distrofia muscular Aside from seeing the telethon on Labor ... which weakens different muscle groups in various ways: Duchenne (pronounced: due-SHEN) muscular dystrophy (DMD) , the most ...

  17. Muscular Dystrophy

    MedlinePlus

    ... be affected. Limb-girdle muscular dystrophy (LGMD) affects boys and girls equally, weakening muscles in the shoulders and upper ... weakness and poor muscle tone. Occurring in both girls and boys, it can have different symptoms. It varies in ...

  18. Fuchs dystrophy

    MedlinePlus

    ... KR. The corneal dystrophies. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology . 2013 ed. Philadelphia, PA: Lippincott ... stripping automated endothelial keratoplasty. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology . 2013 ed. Philadelphia, PA: Lippincott, ...

  19. Facioscapulohumeral Dystrophy.

    PubMed

    Wang, Leo H; Tawil, Rabi

    2016-07-01

    Facioscapulohumeral muscular dystrophy (FSHD) is a clinically recognizable and relatively common muscular dystrophy. It is inherited mostly as an autosomal dominant disease or in a minority of cases, in a digenic pattern. The disease manifestation is variable and most likely dependent on genetic and epigenetic factors. We review the history, epidemiology, clinical presentation, and genetics of the disease, present the recently elucidated molecular pathogenesis, discuss the pathology and the possible consequence of the inflammation seen in the muscle biopsies, and consider future treatments.

  20. [Genetic diagnostic testing in inherited retinal dystrophies].

    PubMed

    Kohl, S; Biskup, S

    2013-03-01

    Inherited retinal dystrophies are clinically and genetically highly heterogeneous. They can be divided according to the clinical phenotype and course of the disease, as well as the underlying mode of inheritance. Isolated retinal dystrophies (i.e., retinitis pigmentosa, Leber's congenital amaurosis, cone and cone-rod dystrophy, macular dystrophy, achromatopsia, congenital stationary nightblindness) and syndromal forms (i.e., Usher syndrome, Bardet-Biedl syndrome) can be differentiated. To date almost 180 genes and thousands of distinct mutations have been identified that are responsible for the different forms of these blinding illnesses. Until recently, there was no adequate diagnostic genetic testing available. With the development of the next generation sequencing technologies, a comprehensive genetic screening analysis for all known genes for inherited retinal dystrophies has been established at reasonable costs and in appropriate turn-around times. Depending on the primary clinical diagnosis and the presumed mode of inheritance, different diagnostic panels can be chosen for genetic testing. Statistics show that in 55-80 % of the cases the genetic defect of the inherited retinal dystrophy can be identified with this approach, depending on the initial clinical diagnosis. The aim of any genetic diagnostics is to define the genetic cause of a given illness within the affected patient and family and thereby i) confirm the clinical diagnosis, ii) provide targeted genetic testing in family members, iii) enable therapeutic intervention, iv) give a prognosis on disease course and progression and v) in the long run provide the basis for novel therapeutic approaches and personalised medicine.

  1. Muscular dystrophy - resources

    MedlinePlus

    Resources - muscular dystrophy ... The following organizations are good resources for information on muscular dystrophy : Muscular Dystrophy Association -- www.mdausa.org National Institute of Neurological Disorders and Stroke -- www.ninds.nih. ...

  2. Transgenic overexpression of the α7 integrin reduces muscle pathology and improves viability in the dyW mouse model of merosin-deficient congenital muscular dystrophy type 1A

    PubMed Central

    Doe, Jinger A.; Wuebbles, Ryan D.; Allred, Erika T.; Rooney, Jachinta E.; Elorza, Margaret; Burkin, Dean J.

    2011-01-01

    Merosin-deficient congenital muscular dystrophy 1A (MDC1A) is a devastating neuromuscular disease that results in children being confined to a wheelchair, requiring ventilator assistance to breathe and premature death. MDC1A is caused by mutations in the LAMA2 gene, which results in the partial or complete loss of laminin-211 and laminin-221, the major laminin isoforms found in the basal lamina of skeletal muscle. MDC1A patients exhibit reduced α7β1 integrin; however, it is unclear how the secondary loss of α7β1 integrin contributes to MDC1A disease progression. To investigate whether restoring α7 integrin expression can alleviate the myopathic phenotype observed in MDC1A, we produced transgenic mice that overexpressed the α7 integrin in the skeletal muscle of the dyW−/− mouse model of MDC1A. Enhanced expression of the α7 integrin restored sarcolemmal localization of the α7β1 integrin to laminin-α2-deficient myofibers, changed the composition of the muscle extracellular matrix, reduced muscle pathology, maintained muscle strength and function and improved the life expectancy of dyW−/− mice. Taken together, these results indicate that enhanced expression of α7 integrin